WO2023068886A1 - 원통형 배터리, 그리고 이를 포함하는 배터리 팩 및 자동차 - Google Patents

원통형 배터리, 그리고 이를 포함하는 배터리 팩 및 자동차 Download PDF

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Publication number
WO2023068886A1
WO2023068886A1 PCT/KR2022/016196 KR2022016196W WO2023068886A1 WO 2023068886 A1 WO2023068886 A1 WO 2023068886A1 KR 2022016196 W KR2022016196 W KR 2022016196W WO 2023068886 A1 WO2023068886 A1 WO 2023068886A1
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Prior art keywords
active material
electrode
battery
cylindrical battery
positive electrode
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PCT/KR2022/016196
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English (en)
French (fr)
Korean (ko)
Inventor
조민기
민건우
Original Assignee
주식회사 엘지에너지솔루션
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Priority to CA3235198A priority Critical patent/CA3235198A1/en
Priority to JP2023544574A priority patent/JP2024505868A/ja
Priority to EP22884107.8A priority patent/EP4293802A1/de
Publication of WO2023068886A1 publication Critical patent/WO2023068886A1/ko

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L50/00—Electric propulsion with power supplied within the vehicle
    • B60L50/50—Electric propulsion with power supplied within the vehicle using propulsion power supplied by batteries or fuel cells
    • B60L50/60—Electric propulsion with power supplied within the vehicle using propulsion power supplied by batteries or fuel cells using power supplied by batteries
    • B60L50/64—Constructional details of batteries specially adapted for electric vehicles
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0422—Cells or battery with cylindrical casing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0431—Cells with wound or folded electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/386—Silicon or alloys based on silicon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/107—Primary casings; Jackets or wrappings characterised by their shape or physical structure having curved cross-section, e.g. round or elliptic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/172—Arrangements of electric connectors penetrating the casing
    • H01M50/174—Arrangements of electric connectors penetrating the casing adapted for the shape of the cells
    • H01M50/179—Arrangements of electric connectors penetrating the casing adapted for the shape of the cells for cells having curved cross-section, e.g. round or elliptic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/183—Sealing members
    • H01M50/184—Sealing members characterised by their shape or structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/183—Sealing members
    • H01M50/186—Sealing members characterised by the disposition of the sealing members
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/533—Electrode connections inside a battery casing characterised by the shape of the leads or tabs
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/538—Connection of several leads or tabs of wound or folded electrode stacks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/543—Terminals
    • H01M50/552—Terminals characterised by their shape
    • H01M50/559—Terminals adapted for cells having curved cross-section, e.g. round, elliptic or button cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/586—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries inside the batteries, e.g. incorrect connections of electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/59—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries characterised by the protection means
    • H01M50/593—Spacers; Insulating plates
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to a cylindrical battery, a battery pack including the cylindrical battery, and a vehicle.
  • a jelly roll having a shape in which a positive electrode tab and a negative electrode tab extend vertically in a height direction of a battery housing may be applied to maximize power collection efficiency.
  • a current collector plate may be used as an intermediate medium for connecting each of the positive electrode tab and the negative electrode tab to the electrode terminal and the battery housing.
  • the positive current collector plate covers one side of the jelly roll and is coupled to the positive tab
  • the negative current collector plate covers the other side of the jelly roll and is coupled to the negative tab.
  • the positive current collector plate may be electrically connected to the electrode terminal
  • the negative current collector plate may be electrically connected to the battery housing.
  • a relatively large empty space may be formed between the negative current collector plate and the cap plate.
  • an empty space may be formed between a bottom surface of the battery housing positioned opposite the cap plate and the positive current collector plate.
  • secondary batteries having high ease of application according to product groups and electrical characteristics such as high energy density are used not only for portable devices but also for electric vehicles (EVs) driven by electric sources, hybrid electric vehicles (HEVs) ), etc. are commonly applied.
  • EVs electric vehicles
  • HEVs hybrid electric vehicles
  • a battery pack is formed by connecting a plurality of batteries in series.
  • a battery pack is configured by connecting a plurality of batteries in parallel according to a charge/discharge capacity required for the battery pack. Accordingly, the number of batteries included in the battery pack and the type of electrical connection may be variously set according to a required output voltage and/or charge/discharge capacity.
  • a separator which is an insulator, is interposed between a positive electrode and a negative electrode, and the electrode assembly in the form of a jelly roll is formed by winding the separator, and the electrode assembly is inserted together with an electrolyte into the battery housing to form a battery.
  • strip-shaped electrode tabs may be connected to the uncoated portions of the positive electrode and the negative electrode, and the electrode tab electrically connects the electrode assembly and the electrode terminal exposed to the outside.
  • the positive electrode terminal is a cap plate of a sealing body sealing the opening of the battery housing
  • the negative electrode terminal is the battery housing.
  • a cylindrical battery having a structure in which the positive and negative uncoated regions are located at the upper and lower ends of the jelly roll type electrode assembly, and a current collecting plate is welded to the uncoated region to improve the current collection efficiency. (a so-called tab-less cylindrical battery) was presented.
  • FIG. 1 to 4 are views showing a manufacturing process of a tab-less cylindrical battery.
  • 1 shows the structure of an electrode
  • FIG. 2 shows a winding process of an electrode
  • FIG. 3 shows a process of welding a current collector plate to a bent surface of an uncoated portion
  • 4 is a cross-sectional view of the tab-less cylindrical battery cut in the longitudinal direction (Y).
  • the positive electrode 210 and the negative electrode 211 have a structure in which an active material 221 is coated on a sheet-shaped current collector 220, and a long side of one side along a winding direction X. It includes an uncoated portion 222 .
  • the electrode assembly (A) is manufactured by sequentially stacking a positive electrode 210 and a negative electrode 211 together with two sheets of separator 212 as shown in FIG. 12 and then winding them in one direction (X). At this time, the uncoated portions of the positive electrode 210 and the negative electrode 211 are disposed in opposite directions.
  • the uncoated portion 210a of the positive electrode 210 and the uncoated portion 211a of the negative electrode 211 are bent toward the core. After that, the current collector plates 230 and 231 are welded and coupled to the uncoated portions 10a and 11a, respectively.
  • the current collector plates 230 and 231 are connected to external electrode terminals, and the current path winds the electrode assembly A. Since it is formed with a large cross-sectional area along the axial direction (see arrow), it has the advantage of lowering the resistance of the battery. This is because resistance is inversely proportional to the cross-sectional area of the path through which current flows.
  • the conventional tab-less cylindrical battery 240 includes a battery housing 241 and a sealing body 242 as shown in FIG. 14 .
  • the sealing body 242 includes a cap plate 242a, a sealing gasket 242b and a connection plate 242c.
  • the sealing gasket 242b surrounds the edge of the cap plate 242a and is fixed by the crimping part 243 .
  • the electrode assembly (A) is fixed in the battery housing 241 by the beading part 244 to prevent up and down movement.
  • the positive terminal is the cap plate 242a of the enclosure 242 and the negative terminal is the battery housing 241 .
  • the collector plate 230 coupled to the uncoated portion 210a of the positive electrode 210 is electrically connected to the connection plate 242c attached to the cap plate 242a through the strip-shaped lead 245 .
  • the collector plate 231 coupled to the uncoated portion 211a of the negative electrode 211 is electrically connected to the bottom of the battery housing 241 .
  • the insulator 246 covers the collector plate 230 to prevent a short circuit from being caused by contact between the battery housing 241 having a different polarity and the non-coated portion 210a of the positive electrode 210 .
  • a lead 245 in the form of a strip is used.
  • the lead 245 is separately attached to the current collector 230 or manufactured integrally with the current collector 230 .
  • the lead 245 is in the form of a thin strip, its cross-sectional area is small, so that a lot of heat is generated when a rapid charging current flows.
  • excessive heat generated in the lead 245 is transmitted to the side of the electrode assembly A and causes the separator 212 to shrink, thereby causing an internal short circuit, which is a major cause of thermal runaway.
  • Lid 245 also takes up significant installation space within battery housing 241 . Therefore, the cylindrical battery 240 including the lead 245 has low space efficiency, and thus has limitations in increasing energy density.
  • the cap plate 242a of the sealing body 242 and the bottom surface of the battery housing 241 must be connected to bus bar parts. As a result, space efficiency is reduced.
  • a battery pack mounted on an electric vehicle includes hundreds of cylindrical batteries 240 . Therefore, the inefficiency of the electrical wiring causes considerable inconvenience during the assembly process of the electric vehicle and maintenance of the battery pack.
  • a positive electrode active material in the form of a single particle or quasi-single particle having a relatively large primary particle size has been developed.
  • the electrode was broken in a state where the porosity was not achieved to a target level, and there was a problem in that the resistance characteristics and charge/discharge efficiency of the lithium secondary battery were not good.
  • the present invention has been devised in consideration of the above-described problems, and an object of the present invention is to prevent damage to an electrical coupling portion caused by movement of a jelly roll in a battery housing.
  • the present invention in the manufacture of a cylindrical battery, prevents the movement of the jelly roll by utilizing previously applied parts, thereby preventing the complexity of the manufacturing process and the increase in manufacturing cost caused by the application of additional parts. It can also be used for other purposes.
  • the present invention has been invented on the background of the above-mentioned prior art, and aims to reduce the internal resistance of the cylindrical battery and increase the energy density by improving the electrode terminal structure of the cylindrical battery to increase space efficiency in the battery housing.
  • Another technical problem of the present invention is to improve the internal heat generation problem occurring during rapid charging by improving the electrode terminal structure of the cylindrical battery to enlarge the cross-sectional area of the current path.
  • Another technical problem of the present invention is to provide a cylindrical battery having an improved structure in which an electrical wiring work for series and/or parallel connection of the cylindrical batteries can be performed on one side of the cylindrical battery.
  • Another technical problem of the present invention is to provide a battery pack manufactured using a cylindrical battery having an improved structure and a vehicle including the battery pack.
  • Another technical problem of the present invention is to provide an electrode that can implement excellent thermal stability, high electrical conductivity and high rolling characteristics by applying a single particle or quasi-single particle as a cathode active material, and an electrode assembly including the same.
  • Another technical problem of the present invention is to provide an electrode assembly with improved energy density by including a silicon-based negative electrode active material in the negative electrode.
  • Another technical problem of the present invention is to provide an electrode assembly in which the section of the cathode active material section is increased without worrying about precipitation of lithium.
  • Another technical problem of the present invention is to provide a cylindrical battery that can exhibit excellent thermal stability even when the volume of the battery increases due to an increase in form factor.
  • a cylindrical battery for solving the above problems is an electrode assembly including a first electrode having a first uncoated portion and a second electrode having a second uncoated portion; a battery housing accommodating the electrode assembly through an opening formed at one side; a first collector plate coupled to the first uncoated portion and positioned within the battery housing; a cap plate covering the opening; a sealing spacer configured to prevent movement of the electrode assembly and enhance sealing force of the battery housing; an electrode terminal riveted through a through hole formed in a closed portion provided opposite to the open portion of the battery housing and electrically connected to the second uncoated portion; and an insulating gasket interposed between the electrode terminal and the through hole.
  • the electrode terminal may include a body portion inserted into the through hole; an outer flange portion extending from a circumference of one side of the body portion exposed through an outer surface of the closure portion along the outer surface; an inner flange portion extending from the circumference of the other side of the body exposed through the inner surface of the closure toward the inner surface; and a flat portion provided inside the inner flange portion.
  • the sealing spacer may include a flow preventing part interposed between the first current collector plate and the cap plate; a sealing portion interposed between the battery housing and the cap plate; and a connecting portion connecting between the flow preventing portion and the sealing portion.
  • the flow prevention part may have a height corresponding to a distance between the first current collector plate and the cap plate.
  • the flow prevention part may be located at a central portion on one surface of the electrode assembly.
  • the flow prevention part may include a spacer hole formed at a position corresponding to the winding center hole of the electrode assembly.
  • the sealing part may have a shape extending along an inner circumferential circumference of the battery housing.
  • connection part may include a plurality of extension legs radially extending from the flow prevention part.
  • the plurality of extension legs may be configured not to contact the first current collector plate.
  • the plurality of extension legs may be configured not to contact the cap plate.
  • Inner surfaces of the flat part and the closed part may be parallel to each other.
  • An angle between the inner flange portion and the inner surface of the closure portion may range from 0 degrees to 60 degrees or less.
  • a recessed portion may be provided between the inner flange portion and the flat portion.
  • the recess portion may have a cross-sectional structure of an asymmetric groove.
  • the asymmetric groove may include a side wall of the flat part and an inclined surface of the inner flange part connected to an end of the side wall.
  • the sidewall may be perpendicular to an inner surface of the closure part.
  • a thickness of the inner flange portion may decrease as the distance from the body portion increases.
  • the insulating gasket may include an outer gasket interposed between the outer flange portion and the outer surface of the closure portion; and an inner gasket interposed between the inner flange portion and an inner surface of the closure portion, and the inner gasket and the outer gasket may have different thicknesses depending on positions.
  • a thickness of an area interposed between an inner edge of the through hole connected to an inner surface of the closure part and the inner flange portion among areas of the inner gasket may be relatively smaller than other areas.
  • An inner edge of the through hole may include an opposing surface facing the inner flange portion.
  • the inner gasket may extend longer than the inner flange portion.
  • a height of the flat portion based on an inner surface of the closure portion may be equal to or greater than a height of an end portion of the inner gasket.
  • a height of the flat portion based on an inner surface of the closure portion may be equal to or greater than a height of an end portion of the inner flange portion.
  • the active material layer of the second electrode may include a cathode active material including a single particle, quasi-single particle, or a combination thereof, and D min , which is a minimum particle size appearing in the cumulative volume distribution of the cathode active material, may be 1.0 ⁇ m or more.
  • D 50 when the volume cumulative amount is 50% may be 5.0 ⁇ m or less
  • the maximum particle size D max appearing in the volume cumulative distribution of the positive electrode active material is 12 ⁇ m to 12 ⁇ m. It may be 17 ⁇ m.
  • the cathode active material has a unimodal particle size distribution showing a single peak in a volume cumulative particle size distribution graph, and a particle size distribution (PSD) represented by the following formula may be 3 or less :
  • Particle size distribution (PSD) (D max - D min )/D 50
  • the single particle, quasi-single particle, or a combination thereof may be included in an amount of 95wt% to 100wt% based on the total weight of the positive electrode active material included in the active material layer of the second electrode.
  • the cathode active material may include a lithium nickel-based oxide containing 80 mol% or more of Ni based on the total number of moles of the transition metal.
  • the active material layer of the second electrode may have a porosity of 15% to 23%, and the active material layer of the second electrode may include flaky graphite in a weight ratio of 0.05wt% to 5wt%.
  • the active material layer of the second electrode may further include carbon nanotubes.
  • the active material layer of the first electrode may include a silicon-based negative active material and a carbon-based negative active material, and the silicon-based negative active material and the carbon-based negative active material may be included in a weight ratio of 1:99 to 20:80.
  • a battery pack according to an embodiment of the present invention includes a cylindrical battery according to an embodiment of the present invention as described above; and a pack housing accommodating a plurality of the cylindrical batteries.
  • An automobile according to an embodiment of the present invention includes the battery pack according to an embodiment of the present invention as described above.
  • the motion of the jelly roll is minimized in the battery housing, so that damage to the electrical connection portion can be prevented.
  • the complexity of the manufacturing process and the increase in manufacturing cost can be prevented by using the previously applied parts instead of additionally applying parts for preventing the flow of the jelly roll.
  • internal resistance of the cylindrical battery may be lowered and energy density may be increased by improving space efficiency in the battery housing by improving the electrode terminal structure of the cylindrical battery.
  • the problem of internal heat generated during rapid charging can be improved by improving the structure of the electrode terminal of the cylindrical battery to enlarge the cross-sectional area of the current path.
  • electrical wiring work for series and/or parallel connection of the cylindrical batteries may be performed on one side of the cylindrical batteries.
  • a battery pack manufactured using a cylindrical battery having an improved structure and a vehicle including the battery pack may be provided.
  • the thermal stability of the battery can be further improved by including the positive electrode active material powder having D min of 1.0 ⁇ m or more in the positive electrode.
  • the positive electrode active material powder having D min of 1.0 ⁇ m or more in the positive electrode.
  • D min minimum particle size
  • the positive electrode includes a positive electrode active material powder in which D 50 , D max , and particle size distribution (PSD) are appropriately adjusted, thereby minimizing an increase in resistance due to application of single particles, Excellent capacitance and output characteristics can be realized.
  • D 50 , D max , and particle size distribution (PSD) are appropriately adjusted, thereby minimizing an increase in resistance due to application of single particles, Excellent capacitance and output characteristics can be realized.
  • the conductivity of the electrode may be improved by including a single-grain cathode active material coated with a conductive coating layer or by containing novel CNTs as a conductive material.
  • the flaky graphite is included in the cathode active material layer, when the cathode active material layer is rolled, the flaky graphite provides a sliding effect to the cathode active material to improve the rolling characteristics of the electrode, the electrode The porosity can be reduced to a target level. Accordingly, stability, initial resistance characteristics, and charge/discharge efficiency of the cylindrical battery are improved.
  • a higher energy density can be realized by including a silicon-based negative electrode active material having a large capacity in the negative electrode.
  • the loading reduction portion having a small loading amount of the cathode active material is included in the cathode, the section of the cathode active material portion may be increased without worrying about lithium precipitation.
  • 1 is a plan view showing the structure of an electrode used in a conventional tap-less cylindrical battery.
  • FIG. 2 is a view showing a winding process of an electrode assembly included in a conventional tab-less cylindrical battery.
  • FIG. 3 is a view showing a process of welding a current collector plate to a curved surface of an uncoated portion in the electrode assembly of FIG. 2 .
  • FIG. 4 is a cross-sectional view of a conventional tab-less cylindrical battery cut in the longitudinal direction (Y).
  • FIG. 5 is a perspective view showing the appearance of a cylindrical battery according to an embodiment of the present invention.
  • FIG. 6 is a cross-sectional view showing the internal structure of a cylindrical battery according to an embodiment of the present invention.
  • FIG. 7 is a perspective view showing an exemplary form of a first current collector applied to the present invention.
  • FIG. 8 is a partial cross-sectional view showing a region to which an integrated spacer according to the present invention is applied.
  • FIG. 9 is a perspective view showing an exemplary form of the integral spacer of the present invention.
  • FIG. 10 is a plan view showing the bottom surface of the cylindrical battery of the present invention.
  • FIG. 11 is a partial cross-sectional view showing a region to which an insulator of the present invention is applied.
  • FIG. 12 is a partial cross-sectional view showing a coupling structure between a current collector plate and an electrode tab according to the present invention.
  • FIG. 13 is a schematic diagram illustrating a battery pack according to an embodiment of the present invention.
  • FIG. 14 is a conceptual diagram illustrating a vehicle according to an embodiment of the present invention.
  • 15 is a cross-sectional view showing a riveting structure of an electrode terminal according to an embodiment of the present invention.
  • FIG. 16 is an enlarged cross-sectional view of a portion indicated by a dotted circle in FIG. 15 .
  • 17 is a cross-sectional view of a cylindrical battery according to an embodiment of the present invention taken along a longitudinal direction (Y).
  • FIG. 18 is a plan view exemplarily showing an electrode structure according to a preferred embodiment of the present invention.
  • 19 is a cross-sectional view of an electrode assembly obtained by applying a segmental structure of an electrode according to an embodiment of the present invention to a first electrode and a second electrode, cut along a longitudinal direction (Y).
  • 20 is a cross-sectional view of the electrode assembly in which the uncoated portion is bent along the length direction (Y) according to an embodiment of the present invention.
  • 21 is a scanning micrograph of a carbon nanotube (existing CNT) commonly used in the prior art.
  • FIG. 22 is a scanning micrograph of a novel CNT according to an embodiment of the present invention.
  • 23 is a table showing a comparison of physical properties of reference CNTs and new CNTs.
  • 24 to 27 are graphs showing sheet resistance and high-temperature lifespan characteristics for each conductive material ratio when single-grain active material particles are applied as the positive electrode active material.
  • Example 29 is a SEM picture of the cathode active material used in Example 2-1 of the present invention.
  • Example 30 is a SEM picture of the cathode active material used in Example 2-2 of the present invention.
  • Example 31 is a SEM picture of the cathode active material used in Comparative Example 2-2 of the present invention.
  • 32 is a graph showing hot box test results of 4680 cells manufactured according to Example 1 of the present invention.
  • Example 34 is a graph showing hot box test results of 4680 cells manufactured by Sample 1 of Example 2-1 and Comparative Example 2-1 of the present invention.
  • Example 35 is a graph showing hot box test results of 4680 cells manufactured by Samples 2 and 3 of Example 2-1, Samples 1 and 2 of Example 2-2, and Comparative Example 2-2 of the present invention.
  • Example 36 is a cross-sectional SEM image of the anode prepared in Example 2-1 of the present invention.
  • DCIR increase capacity retention and resistance increase
  • FIG. 40 is a view showing an electrode assembly according to an embodiment of the present invention.
  • FIG. 41 is a cross-sectional view showing a cross section taken along the line A-A' of FIG. 40;
  • 42 and 43 are diagrams illustrating a process of manufacturing an anode according to an embodiment of the present invention.
  • FIG 44 is a perspective view showing a negative electrode according to an embodiment of the present invention.
  • 45 and 46 are diagrams illustrating a process of manufacturing an anode according to an embodiment of the present invention.
  • 47 is a perspective view showing an anode according to an embodiment of the present invention.
  • FIG. 48 is a view showing an electrode assembly according to a comparative example of the present invention.
  • 49 is a cross-sectional view showing a cross section taken along the cutting line BB′ of FIG. 48;
  • FIG 50 is a view showing a process of manufacturing a negative electrode according to a comparative example of the present invention.
  • 51 is a view showing a process of manufacturing a positive electrode according to a comparative example of the present invention.
  • FIG. 52 is a graph showing changes in energy density according to the content of the silicon-based negative active material and the presence or absence of doping of the silicon-based negative active material in a battery using a mixture of a silicon-based negative active material and a carbon-based negative active material as the negative electrode active material.
  • a part such as a layer, film, region, plate, etc. is said to be “on” or “on” another part, this includes not only the case where it is “directly on” the other part, but also the case where there is another part in the middle. . Conversely, when a part is said to be “directly on” another part, it means that there is no other part in between.
  • a reference part means to be located above or below the reference part, and to necessarily be located “on” or “on” in the opposite direction of gravity does not mean no.
  • planar image it means when the target part is viewed from above, and when it is referred to as “cross-sectional image”, it means when a cross section of the target part cut vertically is viewed from the side.
  • a cylindrical battery 1 includes an electrode assembly 10, a battery housing 20, a first collector plate 30, a cap plate 40, A sealing spacer 60 and an electrode terminal 50 are included.
  • the cylindrical battery 1 may further include an insulating gasket 54 and/or a second collector plate 70 and/or an insulator 80 in addition to the above components.
  • the electrode assembly 10 includes a first electrode having a first uncoated portion (first electrode tab) 11 and a second uncoated portion (second uncoated portion). and a second electrode having an electrode tab) (12).
  • the electrode uncoated portion or uncoated portion referred to below means an electrode tab.
  • the electrode assembly 10 includes a first electrode having a first polarity, a second electrode having a second polarity, and a separator interposed between the first electrode and the second electrode.
  • the first electrode is a cathode or an anode
  • the second electrode corresponds to an electrode having a polarity opposite to that of the first electrode.
  • the electrode assembly 10 may have, for example, a jelly-roll shape. That is, the electrode assembly 10 may be manufactured by winding a laminate formed by sequentially stacking the first electrode, the separator, and the second electrode at least once.
  • the jelly-roll type electrode assembly 10 may have a winding center hole C formed at its center and extending along a height direction (a direction parallel to the Z-axis). Meanwhile, an additional separator may be provided on the outer circumferential surface of the electrode assembly 10 for insulation from the battery housing 20 .
  • the first electrode includes a first electrode current collector and a first electrode active material layer formed by being coated on one or both surfaces of the first electrode current collector.
  • a first uncoated portion 11 to which the first electrode active material is not applied is present at one end of the first electrode current collector in the width direction (direction parallel to the Z-axis).
  • the first uncoated portion 11 has a shape extending from one end to the other end along the longitudinal direction of the first electrode when viewed from the unfolded state of the first electrode.
  • the first uncoated portion 11 functions as the first electrode tab as described above.
  • the first uncoated portion 11 is provided on one surface of the electrode assembly 10 . More specifically, the first uncoated portion 11 is provided below the electrode assembly 10 accommodated in the battery housing 20 in a height direction (direction parallel to the Z-axis).
  • the second electrode includes a second electrode current collector and a second electrode active material layer formed by being coated on one or both surfaces of the second electrode current collector.
  • a second uncoated portion 12 to which the second electrode active material is not coated is present at the other end of the second electrode current collector in the width direction (direction parallel to the Z-axis).
  • the second uncoated portion 12 has a shape extending from one end to the other end along the longitudinal direction of the second electrode when viewed from the unfolded state of the second electrode.
  • the second uncoated portion 12 functions as the second electrode tab as described above.
  • the second uncoated portion 12 is provided on the other surface of the electrode assembly 10 . More specifically, the second uncoated portion 12 is provided above the electrode assembly 10 accommodated in the battery housing 20 in a height direction (direction parallel to the Z-axis).
  • first uncoated portion 11 and the second uncoated portion 12 are disposed in opposite directions along the height direction of the electrode assembly 10 (parallel to the Z-axis), that is, along the height direction of the cylindrical battery 1. extends out into
  • the positive electrode active material coated on the positive electrode and the negative electrode active material coated on the negative electrode may be used without limitation as long as they are known in the art.
  • the battery housing 20 accommodates the electrode assembly 10 through an opening formed at a lower end thereof.
  • the battery housing 20 is a substantially cylindrical container in which an open part is formed at the lower end and a closed part is formed at the upper end.
  • the battery housing 20 may be made of a conductive material such as metal.
  • the material of the battery housing 20 may be aluminum, for example.
  • a side surface (outer circumferential surface) and an upper surface of the battery housing 20 may be integrally formed.
  • An upper surface (parallel to the X-Y plane) of the battery housing 20 may have a substantially flat shape.
  • the battery housing 20 also accommodates the electrolyte together with the electrode assembly 10 through an opening formed at a lower end.
  • the battery housing 20 is electrically connected to the electrode assembly 10 .
  • the battery housing 20 is connected to the first uncoated portion 11 of the electrode assembly 10 . Accordingly, the battery housing 20 has the same polarity as the first uncoated portion 11 electrically.
  • the battery housing 20 may include a beading portion 21 and a crimping portion 22 formed at a lower end thereof.
  • the beading part 21 is located below the electrode assembly 10 accommodated inside the battery housing 20 .
  • the beading portion 21 is formed by press-fitting the outer circumference of the battery housing 20 .
  • the beading portion 21 partially reduces the inner diameter of the battery housing 20, so that the electrode assembly 10, which may have a size substantially corresponding to the width of the battery housing 20, is formed at the lower end of the battery housing 20. Do not let it come out through the opening formed in the
  • the beading portion 21 may also function as a support portion on which the cap plate 40 is seated.
  • the crimping part 22 is formed below the beading part 21 .
  • the crimping part 22 has an extended and bent shape so as to surround the periphery of the cap plate 40 while the circumferential portion of the sealing spacer 60 is interposed therebetween.
  • the first collector plate 30 is coupled to the first uncoated portion 11 of the electrode assembly 10 and positioned within the battery housing 20 .
  • the first collector plate 30 covers at least a portion of one surface of the lower end of the electrode assembly 10 .
  • the assembly including the electrode assembly 10 and the first collector plate 30 may be inserted into the battery housing 20 through an opening formed at a lower end of the battery housing 20 .
  • the first collector plate 30 is electrically connected to the battery housing 20 . That is, the first collector plate 30 may function as a medium for electrical connection between the electrode assembly 10 and the battery housing 20 .
  • the first current collector 30 may include, for example, a central portion 31, a non-coated portion coupling portion 32, and a housing contact portion 33.
  • the central part 31 is located at the central part on one surface formed at the lower end of the electrode assembly 10 .
  • a first collector plate hole 30a may be provided in the central portion 31 .
  • the first collector plate hole 30a is formed at a position corresponding to the winding center hole C of the electrode assembly 10 .
  • the first collector plate hole 30a may function as a passage for insertion of a welding rod or laser irradiation for coupling between the electrode terminal 50 and the second collector plate 70 to be described later.
  • the first collector plate hole 30a can also function as a passage through which electrolyte can be smoothly impregnated into the electrode assembly 10 when electrolyte is injected.
  • the uncoated portion coupling portion 32 extends from the central portion 31 and is coupled to the first uncoated portion 11 .
  • the uncoated part coupling part 32 may be provided with a plurality of, for example. In this case, each of the plurality of uncoated part coupling parts 32 may have a shape radially extending from the central part 31 .
  • the housing contact portion 33 may extend from the central portion 31 as shown in FIG. 7 or may extend from an end of the uncoated portion coupling portion 32 unlike that shown in FIG. 7 . An end of the housing contact portion 33 may be interposed between the sealing portion 62 of the sealing spacer 60 and the battery housing 20 to be described later, and may come into contact with the battery housing 20, thereby contacting the battery housing 20 and the battery housing 20. Electrical connection between the first current collector plates 30 may be made.
  • the housing contact portion 33 may be provided in plural numbers, for example.
  • the plurality of housing contact portions 33 may have a shape radially extending from the central portion 31, and at least one contact portion 32 between adjacent uncoated portion coupling portions 32 may be formed.
  • a housing contact portion 33 may be located.
  • the plurality of housing contact portions 33 may have a shape extending from the respective ends of the plurality of uncoated portion coupling portions 32 .
  • the cap plate 40 covers an opening formed in the battery housing 20 .
  • the cap plate 40 may be made of, for example, a metal material to secure rigidity.
  • the cap plate 40 forms a lower surface of the cylindrical battery 1 .
  • the cap plate 40 may not have a polarity even if it is made of a conductive metal material. Having no polarity may mean that the cap plate 40 is electrically insulated from the battery housing 20 and the electrode terminal 50 . Accordingly, the cap plate 40 does not function as a positive or negative terminal. Accordingly, the cap plate 40 does not need to be electrically connected to the electrode assembly 10 and the battery housing 20, and the material does not necessarily have to be a conductive metal.
  • the cap plate 40 When the battery housing 20 of the present invention includes the beading part 21 , the cap plate 40 may be seated on the beading part 21 formed in the battery housing 20 . In addition, when the battery housing 20 of the present invention includes the crimping part 22 , the cap plate 40 is fixed by the crimping part 22 . Between the cap plate 40 and the crimping portion 22 of the battery housing 20 , an edge circumferential portion of the sealing spacer 60 is interposed to secure airtightness of the battery housing 20 .
  • the cap plate 40 further includes a venting part 41 to prevent the internal pressure from increasing beyond a predetermined value due to gas generated inside the battery housing 20 .
  • the bent portion 41 corresponds to an area of the cap plate 40 having a smaller thickness than the surrounding area.
  • the venting part 41 is structurally weak compared to the surrounding area. Therefore, when an abnormality occurs in the cylindrical battery 1 and the internal pressure of the battery housing 20 increases to a certain level or more, the venting part 41 is broken and the gas generated inside the battery housing 20 is discharged. It can be.
  • the venting portion 41 may be formed by partially reducing the thickness of the battery housing 20 by notching one side or both sides of the cap plate 40 , for example.
  • the lower end of the cap plate 40 is preferably positioned higher than the lower end of the battery housing 20 .
  • the cap plate 40 does not come into contact with the ground or the bottom surface of the housing. Therefore, it is possible to prevent a phenomenon in which the pressure required for breaking the venting part 41 differs from a design value due to the weight of the cylindrical battery 1, and thus, the smoothness of breaking the venting part 41 can be secured.
  • venting part 41 is continuously formed in a substantially circular shape, but the present invention is not limited thereto.
  • the venting portion 41 may be discontinuously formed on the cap plate 40 in a substantially circular shape, or may be formed in a substantially straight line shape or other shapes.
  • the sealing spacer 60 is configured to prevent the electrode assembly 10 from moving and to enhance the sealing force of the battery housing 20 .
  • the sealing spacer 60 may include, for example, a flow prevention part 61 , a sealing part 62 , and a connection part 63 .
  • the flow prevention part 61 is interposed between the first current collector plate 30 and the cap plate 40 .
  • the flow prevention part 61 may have a height corresponding to a distance between the first current collector plate 30 and the cap plate 40 .
  • the movement preventing part 61 effectively prevents the electrode assembly 10 from moving within the battery housing 20 due to the gap formed between the first current collecting plate 30 and the cap plate 40. can Therefore, the flow prevention part 61 is damaged at the joint between the electrode assembly 10 and the first collector plate 30 and/or the joint between the first collector plate 30 and the battery housing 20. can prevent it from happening.
  • the flow prevention part 61 may be located approximately at the center on one surface of the lower end of the electrode assembly 10 .
  • the flow prevention part 61 may have a spacer hole 60a formed at a position corresponding to the winding center hole C of the electrode assembly 10 .
  • the spacer hole 60a like the above-described first collector plate hole 30a, may function as a passage for inserting a welding rod or a passage for laser irradiation.
  • the spacer hole 60a may also function as a passage through which electrolyte can be smoothly impregnated into the electrode assembly 10 when electrolyte is injected.
  • the sealing part 62 is interposed between the battery housing 20 and the cap plate 40 .
  • the sealing part 62 may have a shape extending along the inner circumference of the battery housing 20 .
  • the sealing part 62 may be bent along the bent shape of the crimping part 22 to cover the edge circumferential area of the cap plate 40 . there is.
  • the sealing part 62 may function as a gasket for improving the fixing force of the cap plate 40 and the sealing force of the battery housing 20 .
  • connection part 63 connects between the flow prevention part 61 and the sealing part 62.
  • the connection part 63 may include, for example, a plurality of extension legs 63a radially extending from the flow prevention part 61 .
  • the plurality of extension legs 63a except for the portion inserted into the crimping portion 22, of the housing contact portion 33 of the first current collector 30 and/or the cap It may be configured not to contact the plate 40 .
  • the connection part 63 may be positioned so as not to overlap with the housing contact part 33 along the height direction (direction parallel to the Z-axis) of the cylindrical battery 1 .
  • the extension legs 63a when the extension legs 63a have a shape extending radially from the flow preventing portion 61 and the plurality of housing contact portions 33 have a shape extending radially from the central portion 31, the extension legs ( 63a) and the housing contact portion 33 may be arranged at staggered positions so as not to overlap each other along the vertical direction. In this case, even if a compressive force in the vertical direction is applied to the battery housing 20 and the shape deformation of the components occurs, the possibility of interference between the extension leg 63a and the housing contact portion 33 can be significantly reduced, thereby reducing the coupling between the components. It can significantly reduce the possibility of problems such as breakage.
  • the sealing spacer 60 even if the shape deformation of the sealing spacer 60 occurs due to a sizing process of compressing the cylindrical battery 1 along the height direction (direction parallel to the Z axis) or other causes, the sealing spacer ( Interference between the connection portion 63 of 60 and the housing contact portion 33 of the first current collector 30 can be minimized.
  • the extension leg 63a when the extension leg 63a is configured not to contact the cap plate 40, even if the battery housing 20 is deformed due to a sizing process or an external impact, the extension leg 63a is deformed. may reduce the likelihood of
  • each component constituting the sealing spacer 60 may be integrally formed.
  • the sealing spacer 60 in which the flow prevention part 61, the sealing part 62, and the connection part 63 are integrated can be manufactured by the injection molding. That is, the cylindrical battery 1 of the present invention, as one component, strengthens the sealing force for the opening of the battery housing 20 and electrodes through modification of the gasket part used to seal the opening of the battery housing 20. All of the flow prevention effects of the assembly 10 can be obtained. Therefore, according to the present invention, the complexity of the manufacturing process and the increase in manufacturing cost caused by the application of additional parts can be prevented.
  • the electrode terminal 50 is electrically connected to the second uncoated portion 12 of the electrode assembly 10.
  • the electrode terminal 50 may pass through, for example, a substantially central portion of a closed portion formed at an upper end of the battery housing 20 .
  • a portion of the electrode terminal 50 may be exposed to the upper portion of the battery housing 20 and the remaining portion may be positioned inside the battery housing 20 .
  • the electrode terminal 50 may be fixed on the inner surface of the closed portion of the battery housing 20 by, for example, riveting.
  • the closing portion 20a formed at the top of the battery housing 20 It can function as a first electrode terminal having a first polarity.
  • the electrode terminal 50 is electrically connected to the second uncoated portion 12 of the electrode assembly 10, the electrode terminal 50 exposed to the outside of the battery housing 20 is the second electrode terminal. can function as
  • the cylindrical battery 1 of the present invention has a structure in which a pair of electrode terminals 60 and 20a are located in the same direction. Therefore, in the case of electrically connecting a plurality of cylindrical batteries 1 , it is possible to dispose an electrical connection component such as a bus bar on only one side of the cylindrical battery 1 . This can lead to simplification of the battery pack structure and improvement of energy density.
  • the cylindrical battery 1 has a structure in which one surface of the battery housing 20 having a substantially flat shape can be used as a first electrode terminal, so that an electrical connection part such as a bus bar is connected to the first electrode terminal. When bonding, a sufficient bonding area can be secured. Accordingly, in the cylindrical battery 1, sufficient bonding strength between the electrical connecting part and the first electrode terminal can be secured, and resistance at the bonding portion can be reduced to a desirable level.
  • the electrode terminal 50 when the electrode terminal 50 functions as the second electrode terminal, the electrode terminal 50 is electrically insulated from the battery housing 20 having the first polarity. Electrical insulation between the battery housing 20 and the electrode terminal 50 may be realized in various ways. For example, insulation may be realized by interposing an insulating gasket 54 between the electrode terminal 50 and the battery housing 20 . Alternatively, insulation may be realized by forming an insulating coating layer on a part of the electrode terminal 50 . Alternatively, the electrode terminals 50 and the battery housing 20 may be arranged in a spaced apart state so that contact is impossible, but a method of structurally firmly fixing the electrode terminals 50 may be applied. Alternatively, a plurality of methods among the methods described above may be applied together.
  • the insulating gasket 54 when the insulating gasket 54 is applied for electrical insulation and riveting is applied to fix the electrode terminals 50, the insulating gasket 54 is deformed together during riveting of the electrode terminals 50 and the battery It may be bent toward the inner surface of the top closure of the housing 20 .
  • the insulating gasket 54 may be coupled to the battery housing 20 and the electrode terminal 50 by thermal fusion. In this case, airtightness at the bonding interface between the insulating gasket 54 and the electrode terminal 50 and at the bonding interface between the insulating gasket 54 and the battery housing 20 may be enhanced.
  • the second current collector 70 is coupled to an upper portion of the electrode assembly 10 .
  • the second collector plate 70 is made of a conductive metal material and coupled to the second uncoated portion 12 .
  • the coupling between the second uncoated portion 12 and the second current collecting plate 70 may be performed by, for example, laser welding.
  • the second collector plate 70 may be coupled to a coupling surface formed by bending an end portion of the second uncoated portion 12 in a direction parallel to the second collector plate 70 .
  • the bending direction of the second uncoated portion 12 may be, for example, a direction toward the winding center of the electrode assembly 10 .
  • the space occupied by the second uncoated portion 12 is reduced, thereby improving energy density.
  • bonding force may be improved and resistance may be reduced.
  • the coupling structure and coupling method between the second uncoated portion 12 and the second collector plate 70 as described above may be equally applied to the coupling between the first uncoated portion 11 and the first collector plate 30. there is.
  • the insulator 80 is formed between the closing part formed on the upper end of the battery housing 20 and the upper end of the electrode assembly 10 or between the closing part and the second collector plate 70. intervene
  • the insulator 80 may be made of, for example, an insulating resin material. The insulator 80 prevents contact between the electrode assembly 10 and the battery housing 20 and/or prevents contact between the electrode assembly 10 and the second collector plate 70 .
  • the insulator 80 may also be interposed between the upper end of the outer circumferential surface of the electrode assembly 10 and the inner surface of the battery housing 20 . In this case, it is possible to prevent a short circuit from being caused by contact of the second uncoated portion 12 of the electrode assembly 10 with the inner surface of the sidewall portion of the battery housing 20 .
  • the insulator 80 may have a height corresponding to a distance between the closing portion formed at the top of the battery housing 20 and the electrode assembly 10 or a distance between the closing portion and the second current collecting plate 70. . In this case, it is possible to prevent the electrode assembly 10 from moving inside the battery housing 20, thereby significantly reducing the risk of damage to the coupling part for electrical connection between parts. When the insulator 80 is applied together with the sealing spacer 60 described above, the flow prevention effect of the electrode assembly 10 can be maximized.
  • the insulator 80 may have an insulator hole 80a formed at a position corresponding to the winding center hole C of the electrode assembly 10 .
  • the electrode terminal 50 may directly contact the second current collector 70 through the insulator hole 80a.
  • the cylindrical battery may be, for example, a cylindrical battery having a form factor ratio (defined as the diameter of the cylindrical battery divided by the height, i.e., the ratio of the diameter ( ⁇ ) to the height (H)) of greater than about 0.4. .
  • a form factor ratio defined as the diameter of the cylindrical battery divided by the height, i.e., the ratio of the diameter ( ⁇ ) to the height (H)
  • the form factor means a value representing the diameter and height of a cylindrical battery.
  • a cylindrical battery according to an embodiment of the present invention may be, for example, 46110 cells, 48750 cells, 48110 cells, 48800 cells, or 46800 cells.
  • the first two numbers indicate the diameter of the cell
  • the next two numbers indicate the height of the cell
  • the last number 0 indicates that the cross section of the cell is circular.
  • a battery according to an embodiment of the present invention may be a cylindrical battery having a substantially cylindrical shape, a diameter of about 46 mm, a height of about 110 mm, and a form factor ratio of about 0.418.
  • a battery according to another embodiment may be a cylindrical cell having a diameter of about 48 mm, a height of about 75 mm, and a form factor ratio of about 0.640.
  • a battery according to another embodiment may be a cylindrical battery having a substantially cylindrical shape, a diameter of about 48 mm, a height of about 110 mm, and a form factor ratio of about 0.418.
  • a battery according to another embodiment may be a cylindrical cell having a diameter of about 48 mm, a height of about 80 mm, and a form factor ratio of about 0.600.
  • a battery according to another embodiment may be a cylindrical battery having a substantially cylindrical shape, a diameter of about 46 mm, a height of about 80 mm, and a form factor ratio of about 0.575.
  • batteries with a form factor ratio of approximately 0.4 or less have been used. That is, conventionally, for example, 18650 cells, 21700 cells, etc. have been used. For an 18650 cell, its diameter is approximately 18mm, its height is approximately 65mm, and the form factor ratio is approximately 0.277. For a 21700 cell, its diameter is approximately 21 mm, its height is approximately 70 mm, and the form factor ratio is approximately 0.300.
  • a battery pack 3 is a battery assembly in which a plurality of cylindrical batteries 1 according to an embodiment of the present invention are electrically connected and accommodating them. It includes a pack housing (2).
  • components such as a bus bar, a cooling unit, and a power terminal for electrical connection are omitted for convenience of illustration.
  • a vehicle 5 may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, and includes a battery pack 3 according to an embodiment of the present invention.
  • the automobile 5 includes a four-wheeled automobile and a two-wheeled automobile.
  • the vehicle 5 operates by receiving power from the battery pack 3 according to an embodiment of the present invention.
  • the cylindrical battery according to the embodiment of the present invention may include electrode terminals riveted to the bottom of the battery housing.
  • FIG. 15 is a cross-sectional view showing a riveting structure of an electrode terminal 50 according to an embodiment of the present invention
  • FIG. 16 is an enlarged cross-sectional view of a portion indicated by a dotted circle.
  • the riveting structure of the electrode terminal 50 is formed in a cylindrical battery housing 20 with one side open and a closed portion 20a of the battery housing 20.
  • An electrode terminal 50 riveted through the through hole 23 and an insulating gasket 54 interposed between the electrode terminal 50 and the through hole 23 may be included.
  • the battery housing 20 is made of a conductive metal material.
  • the battery housing 20 may be made of a steel material, but the present invention is not limited thereto.
  • the electrode terminal 50 is made of a conductive metal material.
  • the electrode terminal 50 may be made of aluminum, but the present invention is not limited thereto.
  • the insulating gasket 54 may be made of a polymer resin having insulating properties and elasticity.
  • the insulating gasket 54 may be made of polypropylene, polybutylene terephthalate, polyfluorinated ethylene, or the like, but the present invention is not limited thereto.
  • the electrode terminal 50 is a body portion 50a inserted into the through hole 23 and a circumference of one side of the body portion 50a exposed through the outer surface of the closing portion 20a of the battery housing 20.
  • An external flange portion 50b extending along the outer surface of the battery housing 20, an inner flange portion extending toward the inner surface from the other circumference of the body portion 50a exposed through the inner surface of the closing portion 20a of the battery housing 20 ( 50c), and a flat portion 50d provided inside the inner flange portion 50c.
  • the inner surface of the flat portion 50d and the closing portion 20a of the battery housing 20 may be parallel to each other.
  • 'parallel' means substantially parallel when observed with the naked eye.
  • the angle ⁇ between the inner flange portion 50c and the inner surface of the battery housing 20 closing portion 20a may be 0 degrees to 60 degrees or less.
  • the size of the angle is determined by the caulking strength when the electrode terminal 50 is installed in the through hole 23 of the battery housing 20 by the caulking method. In one example, as the caulking strength increases, the angle ⁇ may decrease to 0 degree. If the angle exceeds 60 degrees, the sealing effect of the insulating gasket 54 may deteriorate.
  • a recessed portion 55 may be provided between the inner flange portion 50c and the flat portion 50d.
  • the recessed portion 55 may have a cross-sectional structure of an asymmetrical groove.
  • the asymmetrical groove may be approximately V-shaped.
  • the asymmetric groove may include a side wall 55a of the flat portion 50d and an inclined surface 55b of the inner flange portion 50c connected to the end of the side wall 55a.
  • the sidewall 55a may be substantially perpendicular to the inner surface of the battery housing 20 closing portion 20a. 'Vertical' means substantially vertical when observed with the naked eye.
  • the recess portion 55 is made in the shape of a caulking jig when the electrode terminal 50 is installed in the through hole 23 of the battery housing 20 by the caulking method.
  • the thickness of the inner flange portion 50c may decrease as the distance from the body portion 50a of the electrode terminal 50 increases.
  • the insulating gasket 54 includes an outer gasket 54a interposed between the outer flange portion 50b and the outer surface of the closure portion 20a of the battery housing 20, and an inner flange portion 50c.
  • the battery housing 20 may include an inner gasket 54b interposed between the inner surface of the closure 20a.
  • the outer gasket 54a and the inner gasket 54b may have different thicknesses depending on positions.
  • the area of the inner gasket 54b the area interposed between the inner edge 24 of the through hole 23 connected to the inner surface of the closed portion 20a of the battery housing 20 and the inner flange portion 50c
  • the thickness may be relatively small.
  • a minimum thickness point may exist in a gasket region interposed between the inner edge 24 of the through hole 23 and the inner flange portion 50c.
  • the inner edge 24 of the through hole 23 may include a facing surface 25 facing the inner flange portion 50c.
  • upper and lower ends of the inner wall of the through hole 23 perpendicular to the closed portion 20a of the battery housing 20 are chamfered to form a tapered surface toward the electrode terminal 50 .
  • the top and/or bottom of the inner wall of the through hole 23 may be deformed into a smooth curved surface having curvature. In this case, the stress applied to the gasket 54 near the top and/or bottom of the inner wall of the through hole 23 can be more alleviated.
  • the inner gasket 54b forms an angle of 0 degrees to 60 degrees with the inner surface of the closure part 20a of the battery housing 20 and may extend longer than the inner flange part 50c.
  • a height H1 of the flat portion 50d based on the inner surface of the closing portion 20a of the battery housing 20 may be equal to or greater than a height H2 of an end portion of the inner gasket 54b.
  • a height H1 of the flat portion 50d based on the inner surface of the closing portion 20a of the battery housing 20 may be equal to or greater than a height H3 of an end portion of the inner flange portion 50c.
  • the radius R1 from the center of the body portion 50a of the electrode terminal 50 to the edge of the outer flange portion 50b is the radius R2 of the closing portion 20a of the battery housing 20. It may be 10 to 60% as a standard.
  • ratio R1/R2 is adjusted between 10 and 60%, it is possible to appropriately secure the welding space for the electrode terminal 50 and the outer surface of the closing portion 20a of the battery housing 20.
  • the radius R3 from the center of the body portion 50a of the electrode terminal 50 to the edge of the flat portion 50d ranges from 4 to 4 based on the radius R2 of the closing portion 20a of the battery housing 20. may be 30%.
  • R3 When R3 is small, when welding the current collector plate (second collector plate) (see 70 in FIG. 17) to the flat portion 50d of the electrode terminal 50, the welding space becomes insufficient, and the welding area of the electrode terminal 50 becomes As the contact resistance decreases, the contact resistance may increase.
  • R3 should be smaller than R1, and when R3 is large, the thickness of the inner flange portion 50c becomes thinner, so that the inner flange portion 50c compresses the insulating gasket 54. The sealing ability of the insulating gasket 54 is reduced. It can be.
  • the riveting structure of the electrode terminal 50 can be formed using a caulking jig that moves up and down.
  • a preform (not shown) of the electrode terminal 50 is inserted into the through hole 23 formed in the closed portion 20a of the battery housing 20 with an insulating gasket 54 interposed therebetween.
  • a preform refers to an electrode terminal before being riveted.
  • the caulking jig is inserted into the inner space of the battery housing 20 .
  • the caulking jig has grooves and protrusions corresponding to the final shape of the electrode terminal 50 on a surface facing the preform to form the electrode terminal 50 by riveting the preform.
  • the caulking jig is moved downward to press and form the upper part of the preform to transform the preform into a riveted electrode terminal 50 .
  • the outer gasket 54a interposed between the outer flange portion 50b and the outer surface of the closure portion 20a of the battery housing 20 is elastically compressed and its thickness is reduced.
  • the inner gasket 54b portion interposed between the inner edge 24 of the through hole 23 and the preform is elastically compressed by the inner flange portion 50c, and the thickness is further reduced than other areas.
  • the region where the thickness of the inner gasket 54b is intensively reduced is a portion indicated by a dotted line circle in FIG. 16 . Accordingly, sealing performance and airtightness between the riveted electrode terminal 50 and the battery housing 20 are remarkably improved.
  • the insulation gasket 54 is compressed sufficiently to secure a desired sealing strength without being physically damaged during the process of riveting the preform.
  • the insulation gasket 54 when the labet gasket 54 is made of polybutylene terephthalate, the insulation gasket 54 preferably has a compression rate of 50% or more at the point where it is compressed to a minimum thickness.
  • the compressibility is the ratio of the change in thickness before and after compression to the thickness before compression.
  • the insulating gasket 54 when the insulating gasket 54 is made of polyfluoroethylene, the insulating gasket 54 preferably has a compression ratio of 60% or more at the point where it is compressed to a minimum thickness.
  • the insulating gasket 54 when the insulating gasket 54 is made of polypropylene, the insulating gasket 54 preferably has a compression ratio of 60% or more at the point where it is compressed to a minimum thickness.
  • the pressure forming of the upper part of the preform may be performed step by step by moving the caulking jig up and down at least 12 times. That is, the preform can be deformed several times by pressing and forming in stages. At this time, the pressure applied to the caulking jig may be increased step by step. In this way, it is possible to prevent the insulating gasket 54 from being damaged during the caulking process by distributing the stress applied to the preform several times. In particular, damage to the gasket is minimized when the portion of the inner gasket 54b interposed between the inner edge 24 of the through hole 23 and the preform is intensively compressed by the inner flange portion 50c.
  • the caulking jig presses and forms the upper part of the preform through up and down movement inside the battery housing 20 .
  • a rotary rotary jig used in the prior art may be used for pressure forming of the preform.
  • the rotary rotating jig performs a rotational motion while tilted at a predetermined angle with respect to the central axis of the battery housing 20 . Therefore, the rotary rotating jig having a large turning radius may cause interference with the inner wall of the battery housing 20 .
  • the depth of the battery housing 20 is large, the length of the rotary rotating jig is correspondingly increased. In this case, as the radius of rotation of the end of the rotary rotating jig increases, press forming of the preform may not be performed properly. Therefore, pressure forming using a caulking jig is more effective than a method using a rotary rotary jig.
  • FIG. 17 is a cross-sectional view of a cylindrical battery 1 according to an embodiment of the present invention taken along a longitudinal direction (Y).
  • Y a longitudinal direction
  • the sheet-shaped first electrode and the second electrode are wound with a separator interposed therebetween, and the uncoated portion 11 of the first electrode is exposed at the bottom.
  • the upper part includes a jelly roll type electrode assembly 10 in which the uncoated portion 12 of the second electrode is exposed.
  • the first electrode may be a negative electrode and the second electrode may be an anode.
  • the reverse is also possible.
  • the winding method of the electrode assembly 10 is substantially the same as the winding method of the electrode assembly used in manufacturing the tab-less cylindrical battery according to the prior art described with reference to FIGS. 1 and 2 .
  • the cylindrical battery 1 also includes a cylindrical battery housing 20 that accommodates the electrode assembly 10 and is electrically connected to the uncoated portion 11 of the first electrode.
  • one side (bottom) of the battery housing 20 is open.
  • the closed portion 20a of the battery housing 20 has a structure in which the electrode terminal 50 is riveted to the through hole 23 through a caulking process.
  • the electrode terminal 50 is formed from the body portion 50a inserted into the through hole 23 and one side circumference of the body portion 50a exposed through the outer surface of the closing portion 20a of the battery housing 20.
  • An outer flange portion 50b extending along the outer surface, and an inner flange portion extending toward the inner surface from the other circumference of the body portion 50a exposed through the inner surface of the closing portion 20a of the battery housing 20 ( 50c) and a flat portion 50d provided inside the inner flange portion 50c.
  • the cylindrical battery 1 may also include an insulating gasket 54 interposed between the electrode terminal 50 and the through hole 23 .
  • the cylindrical battery 1 may also include a seal that seals the open end of the battery housing 20 so as to be insulated from the battery housing 20 .
  • the sealing body may include a non-polar cap plate 40 and a sealing portion 62 interposed between an edge of the cap plate 40 and an open end of the battery housing 20 .
  • the sealing part 62 may be a gasket provided for sealing.
  • the cap plate 40 may be made of a conductive metal material such as aluminum, steel, or nickel.
  • the sealing portion 62 may be made of insulating and elastic polypropylene, polybutylene terephthalate, polyfluorinated ethylene, or the like.
  • the present invention is not limited by the material of the cap plate 40 and the sealing part 62 .
  • the cap plate 40 may include a vent 41 that is ruptured when the pressure inside the battery housing 20 exceeds a critical value.
  • the venting part 41 may be formed on both sides of the cap plate 40 .
  • the venting part 41 may form a continuous or discontinuous circular pattern, a straight line pattern, or other patterns on the surface of the cap plate 40 .
  • the battery housing 20 includes a crimping portion 22 extending and bending inwardly of the battery housing 20 to surround and fix the edge of the cap plate 40 together with the sealing portion 62.
  • a crimping portion 22 extending and bending inwardly of the battery housing 20 to surround and fix the edge of the cap plate 40 together with the sealing portion 62.
  • the battery housing 20 may also include a beading portion 21 press-fitted into the battery housing 20 in a region adjacent to the open end.
  • the beading portion 21 supports the edge of the sealing body, particularly the outer circumferential surface of the sealing portion 62, when the sealing body is clamped by the crimping portion 22.
  • the cylindrical battery 1 may further include a first collector plate 30 welded to the uncoated portion 11 of the first electrode.
  • the first collector plate 30 is made of a conductive metal material such as aluminum, steel, or nickel.
  • at least a portion of an edge that does not contact the uncoated portion 11 of the first electrode is interposed between the beading portion 21 and the sealing portion 62 to prevent the crimping portion 22 from can be fixed by
  • at least a portion of an edge of the first current collector plate 30 may be fixed to an inner circumferential surface of the beading portion 21 adjacent to the crimping portion 22 through welding.
  • the cylindrical battery 1 may also include a second collector plate 70 welded to the uncoated portion 12 of the second electrode.
  • a second collector plate 70 welded to the uncoated portion 12 of the second electrode.
  • at least a portion of the second collector plate 70 for example, a central portion, may be welded to the flat portion 50d of the electrode terminal 50.
  • the welding tool is inserted through the winding center hole C in the core of the electrode assembly 10 to reach the welding point of the second collector plate 70.
  • the electrode terminal 50 supports the welding area of the second current collecting plate 70 when the second current collecting plate 70 is welded to the flat portion 50d of the electrode terminal 50, strong pressure is applied to the welding area. welding quality can be improved.
  • the area of the flat portion 50d of the electrode terminal 50 is large, a wide welding area can also be secured.
  • the internal resistance of the cylindrical battery 1 can be reduced by lowering the contact resistance of the welding region.
  • the face-to-face welding structure of the riveted electrode terminal 50 and the second collector plate 70 is very useful for rapid charging using a high c-rate current. This is because the current density per unit area can be lowered in the cross section in the direction in which the current flows, so that the amount of heat generated in the current path can be lowered than before.
  • any one of laser welding, ultrasonic welding, spot welding, and resistance welding may be used.
  • the area of the flat portion 50d can be differently adjusted according to the welding method, and is preferably 2 mm or more for welding strength and ease of the welding process.
  • the diameter of the flat portion 50d is preferably 4 mm or more.
  • welding strength can be secured, and there is no difficulty in performing the welding process by inserting the laser welding tool into the winding center hole C of the electrode assembly 10.
  • the diameter of the flat portion 50d is preferably greater than or equal to 2 mm.
  • welding strength can be secured, and there is no difficulty in performing the welding process by inserting the ultrasonic welding tool into the winding center hole C of the electrode assembly 10.
  • Cylindrical battery 1 may also further include an insulator 80 .
  • the insulator 80 may be interposed between the second collector plate 70 and the inner surface of the closing portion 20a of the battery housing 20 and between the inner circumferential surface of the sidewall of the battery housing 20 and the electrode assembly 10 .
  • the insulator 80 includes an insulator hole 80a exposing the flat portion 50d of the electrode terminal 50 toward the second current collector 70, and the surface of the second current collector 70 and the electrode One side (upper) edge of the assembly 10 may be covered.
  • the uncoated portions 11 and 12 of the first electrode and/or the second electrode are bent from the outer circumferential side of the electrode assembly 10 to the core side to form bent surfaces on the upper and lower portions of the electrode assembly 10. there is.
  • the first current collector plate 30 is welded to a curved surface formed by bending the uncoated portion 11 of the first electrode
  • the second current collector plate 70 is formed by bending the uncoated portion 12 of the second electrode. It can be welded to the bent surface.
  • the first electrode and/or the second electrode may have an improved structure different from that of the conventional electrode (see FIG. 1).
  • FIG. 18 is a plan view exemplarily showing the structure of an electrode 90 according to a preferred embodiment of the present invention.
  • the electrode 90 includes a sheet-shaped current collector 91 made of a foil of a conductive material, an active material layer 92 formed on at least one surface of the current collector 91, and the current collector 91.
  • a non-coating portion 93 not coated with an active material is included at the end of the long side.
  • the uncoated portion 93 may include a plurality of notched segment pieces 93a.
  • the plurality of segments 93a form a plurality of groups, and the segment segments 93a belonging to each group may have the same height (length in the Y direction) and/or width (length in the X direction) and/or the same spacing.
  • the number of segments 93a belonging to each group may be increased or decreased than shown.
  • the segmental segment 93a may have a trapezoidal shape, but may be deformed into a quadrangular shape, a parallelogram shape, a semicircular shape, or a semielliptical shape.
  • the height of the segment 93a may increase stepwise from the core side to the outer circumferential side.
  • the core-side uncoated portion 93' adjacent to the core side may not include the segment piece 93a, and the height of the core-side uncoated portion 93' may be smaller than other uncoated portion regions.
  • the electrode 90 may include an insulating coating layer 94 covering a boundary between the active material layer 92 and the uncoated portion 93 .
  • the insulating coating layer 94 includes an insulating polymer resin and may optionally further include an inorganic filler.
  • the insulating coating layer 94 serves to prevent an end of the active material layer 92 from contacting an active material layer of opposite polarity through a separator and to structurally support the bending of the segment piece 93a. To this end, when the electrode 90 is wound into an electrode assembly, at least a portion of the insulating coating layer 94 is preferably exposed to the outside from the separator.
  • 19 is a cross-sectional view of the electrode assembly 100 in which the segmental structure of the electrode 90 according to the embodiment of the present invention is applied to the first electrode and the second electrode, cut along the longitudinal direction (Y).
  • the electrode assembly 100 may be manufactured by the winding method described with reference to FIGS. 1 and 2 .
  • the protruding structure of the uncoated portions 11 and 12 extending outside the separator is shown in detail, and the illustration of the winding structure of the first electrode, the second electrode, and the separator is omitted.
  • the uncoated portion 11 protruding downward extends from the first electrode, and the uncoated portion 12 protrudes upward from the second electrode.
  • a pattern in which the heights of the uncoated portions 11 and 12 change is schematically shown. That is, the heights of the uncoated portions 11 and 12 may vary irregularly depending on the position where the cross section is cut. For example, when the side portion of the trapezoidal segment 93a is cut, the height of the uncoated portion in the cross section is lower than that of the segmental segment 93a. Accordingly, it should be understood that the heights of the uncoated portions 11 and 12 shown in the cross-sectional drawing of the electrode assembly 100 correspond to the average height of the uncoated portions included in each winding turn.
  • the uncoated portions 11 and 12 may be bent from the outer circumferential side of the electrode assembly 100 to the core side.
  • the bent portion 101 is indicated by a dotted line box.
  • the bent surfaces 102 are formed on the upper and lower portions of the electrode assembly 100 while overlapping segment segments that are radially adjacent to each other in several layers.
  • the core-side uncoated portion (93' in FIG. 18) has a low height and is not bent, and the height (h) of the innermost segment segment is formed by the core-side uncoated portion 93' without segment structure. equal to or smaller than the radial length (r) of the winding region.
  • the winding center hole C in the core of the electrode assembly 100 is not closed by the bent segments. If the winding center hole C is not closed, there is no difficulty in the electrolyte injection process, and the electrolyte injection efficiency is improved. In addition, welding between the electrode terminal 50 and the second current collector 70 may be easily performed by inserting a welding tool through the winding center hole C.
  • the cap plate 40 of the sealing body does not have a polarity.
  • the first collector plate 30 is connected to the sidewall of the battery housing 20 so that the outer surface of the closure 20a of the battery housing 20 has a polarity opposite to that of the electrode terminal 50 . Therefore, when connecting a plurality of cells in series and/or parallel, using the outer surface of the closure 20a of the battery housing 20 and the electrode terminal 50 to connect the bus bar at the top of the cylindrical battery 1, etc. wiring can be performed. Through this, it is possible to improve energy density by increasing the number of cells that can be mounted in the same space.
  • the "primary particle” is a particle in which no grain boundary appears when observed in a field of view of 5000 to 20000 times using a scanning electron microscope or a backscattered electron rotation pattern analyzer (EBSD). means unit.
  • Average particle diameter of primary particles means an arithmetic average value calculated after measuring the particle diameters of primary particles observed in a scanning electron microscope or EBSD image.
  • Secondary particles are particles formed by aggregation of a plurality of primary particles.
  • secondary particles in which 10 or less primary particles are aggregated are referred to as quasi-single particles in order to distinguish them from conventional secondary particles formed by aggregation of tens to hundreds of primary particles.
  • the "specific surface area” is measured by the BET method, and can be specifically calculated from the nitrogen gas adsorption amount under liquid nitrogen temperature (77K) using BELSORP-mino II of BEL Japan.
  • D min ”, “D 50 ”, and “D max ” are particle size values of the cumulative volume distribution of the positive electrode active material measured using a laser diffraction method. Specifically, D min is the minimum particle size appearing in the volume cumulative distribution, D 50 is the particle size when the volume cumulative amount is 50%, and D max is the maximum particle size appearing in the volume cumulative distribution.
  • D 50 means the average particle diameter of the primary particles.
  • D 50 means the average particle diameter of particles formed by aggregation of primary particles.
  • the particle size value of the volume cumulative distribution is, for example, after dispersing the cathode active material in a dispersion medium, introducing it into a commercially available laser diffraction particle size measuring device (e.g., Microtrac MT 3000) and irradiating ultrasonic waves of about 28 kHz with an output of 60 W. After that, it can be measured by obtaining a volume cumulative particle size distribution graph.
  • a commercially available laser diffraction particle size measuring device e.g., Microtrac MT 3000
  • “consist essentially of A” indicates that it includes component A and any components not mentioned that do not materially affect the basic and novel characteristics of the present invention.
  • Basic and novel features of the present invention include at least one of minimizing particle breakage during battery manufacturing, minimizing gas generated by such particle breakage, and minimizing internal cracks. A person of ordinary skill in the art can recognize the material impact of these properties.
  • the present inventors have found that a single particle composed of one primary particle or less than 10 particles as a cathode active material It was confirmed that the safety of a large-sized cylindrical battery can be dramatically improved when a quasi-single particle type cathode active material, which is an aggregate of primary particles, is used alone.
  • the positive electrode is a positive current collector; and a cathode active material layer formed on at least one side of the cathode current collector, wherein the cathode active material layer may include a cathode active material, and optionally, a conductive material and/or a binder.
  • the cathode may have a structure in which a cathode active material layer is formed on at least one surface or both surfaces of a long sheet-shaped cathode current collector, and the cathode active material layer may include a cathode active material and a binder.
  • the positive electrode is a positive electrode active material, a conductive material, and a binder on one side or both sides of a long sheet-shaped positive electrode current collector, dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrroly It may be prepared by applying a cathode slurry prepared by dispersing in a solvent such as money (NMP), acetone, or water, removing the solvent of the cathode slurry through a drying process, and then rolling. Meanwhile, when the positive electrode slurry is applied, a positive electrode including an uncoated portion (uncoated portion) may be manufactured by not applying the positive electrode slurry to a partial region of the positive electrode current collector, for example, one end of the positive electrode current collector.
  • DMSO dimethyl sulfoxide
  • NMP isopropyl alcohol
  • N-methylpyrroly N-methylpyrroly
  • a cathode slurry prepared by applying a cathode slurry prepared by dispersing in
  • the cathode active material includes single-particle active material particles.
  • the single-particle active material particles may be 90wt% or more, 95wt% or more, 98wt% or more, or 99wt% or more relative to 100wt% of the positive electrode active material.
  • the cathode active material may be composed of only the single-particle active material particles.
  • the single-particle active material particle refers to a single particle, a quasi-single particle, or both.
  • the single particle is a particle composed of one primary particle, and the quasi-single particle is an aggregate of 10 or less primary particles.
  • single-particle active material particles composed of one primary particle or quasi-single-particle form in which 10 or less primary particles are agglomerated are conventional secondary active material particles in which dozens to hundreds of primary particles are aggregated. Since the particle strength is higher than that of the particle-type cathode active material, particle breakage hardly occurs during rolling. In addition, in the case of single-particle active material particles, since the number of primary particles constituting the particle is small, the change due to volume expansion and contraction of the primary particles during charging and discharging is small, and accordingly, cracks inside the particle are remarkably generated. Decrease.
  • the single particle and / or quasi-single particle is 95wt% to 100wt%, preferably 98wt% to 100wt%, more preferably 99wt% to 100wt% based on the weight of the total positive electrode active material included in the positive electrode, More preferably, it is preferably included in an amount of 100wt%.
  • the cathode active material including single particles and/or quasi-single particles according to the present invention has D min of 1.0 ⁇ m or more, 1.1 ⁇ m or more, 1.15 ⁇ m or more, 1.2 ⁇ m or more, 1.25 ⁇ m or more, 1.3 ⁇ m or more, or 1.5 ⁇ m.
  • D min of the cathode active material is less than 1.0 ⁇ m, the line pressure increases during the cathode rolling process, and thus particle breakage is likely to occur, and thermal stability is deteriorated, so that thermal stability cannot be sufficiently secured when applied to a large cylindrical battery.
  • D min of the cathode active material may be 3 ⁇ m or less, 2.5 ⁇ m or less, or 2 ⁇ m or less. If D min is too large, the lithium ion diffusion distance within the particles increases, and resistance and output characteristics may deteriorate.
  • D min of the cathode active material may be 1.0 ⁇ m to 3 ⁇ m, 1.0 ⁇ m to 2.5 ⁇ m, or 1.3 ⁇ m to 2.0 ⁇ m.
  • the cathode active material may have D 50 of 5 ⁇ m or less, 4 ⁇ m or less, or 3 ⁇ m or less, for example, 0.5 ⁇ m to 5 ⁇ m, preferably 1 ⁇ m to 5 ⁇ m, more preferably 2 ⁇ m. to 5 ⁇ m.
  • Single-particle and/or quasi-single-particle type positive electrode active materials have less lithium mobility than secondary particle type positive electrode active materials because there are fewer interfaces between primary particles, which serve as a diffusion path for lithium ions inside the particles. There is a problem with this increase. This increase in resistance intensifies as the size of the particles increases, and when the resistance increases, capacity and output characteristics are adversely affected. Accordingly, by adjusting the D 50 of the positive electrode active material to 5 ⁇ m or less, the diffusion distance of lithium ions inside the positive electrode active material particles is minimized, thereby suppressing an increase in resistance.
  • the cathode active material may have a D max of 12 ⁇ m to 17 ⁇ m, preferably 12 ⁇ m to 16 ⁇ m, and more preferably 12 ⁇ m to 15 ⁇ m.
  • D max of the cathode active material satisfies the above range, resistance characteristics and capacity characteristics are more excellent. If the D max of the positive electrode active material is too large, agglomeration between single particles occurs, and the lithium movement path inside the agglomerated particles becomes long, resulting in poor lithium mobility, which may increase resistance. On the other hand, if the D max of the cathode active material is too small, excessive disintegration is performed. Due to excessive disintegration, D min may decrease to less than 1 ⁇ m, resulting in particle breakage during rolling and deterioration in thermal stability.
  • the positive electrode active material may have a particle size distribution (PSD) of 3 or less, preferably 2 to 3, more preferably 2.3 to 3, represented by the following formula (1).
  • PSD particle size distribution
  • Particle size distribution (PSD) (D max - D min )/D 50
  • the positive electrode active material has the above particle size distribution, the electrode density of the positive electrode can be appropriately maintained, and particle breakage and resistance increase can be effectively suppressed.
  • the cathode active material may have an average particle diameter of primary particles of 5 ⁇ m or less, 4 ⁇ m or less, 3 ⁇ m or less, or 2 ⁇ m or less, for example, 0.5 ⁇ m to 5 ⁇ m, preferably 1 ⁇ m to 5 ⁇ m. , more preferably 2 ⁇ m to 5 ⁇ m.
  • the average particle diameter of the primary particles satisfies the above range, a single particle and/or quasi-single particle positive electrode active material having excellent electrochemical properties may be formed. If the average particle diameter of the primary particles is too small, the number of agglomerations of the primary particles forming the positive electrode active material increases, reducing the effect of suppressing particle breakage during rolling.
  • the diffusion path of lithium may be elongated, increasing resistance and degrading output characteristics.
  • the cathode active material preferably has a unimodal particle size distribution.
  • a bimodal positive electrode active material in which a large particle size positive electrode active material having a large average particle diameter and a small particle size positive electrode active material having a small average particle diameter are mixed and used has been widely used.
  • the increase in resistance can be minimized by using a cathode active material having a unimodal distribution.
  • the cathode active material may include lithium nickel-based oxide, and specifically, may include lithium nickel-based oxide containing 80 mol% or more of Ni based on the total number of moles of transition metal.
  • the lithium nickel-based oxide may include 80 mol% or more and less than 100 mol%, 82 mol% or more and less than 100 mol%, or 83 mol% or more and less than 100 mol% of Ni. As described above, when the lithium nickel-based oxide having a high Ni content is used, high capacity can be realized.
  • the cathode active material may include a lithium nickel-based oxide represented by the following [Formula 1].
  • M 1 may be Mn, Al or a combination thereof, preferably Mn or Mn and Al.
  • M 2 is at least one selected from the group consisting of Zr, W, Y, Ba, Ca, Ti, Mg, Ta, and Nb, preferably one selected from the group consisting of Zr, Y, Mg, and Ti. or more, more preferably Zr, Y, or a combination thereof.
  • the M 2 element is not necessarily included, but when included in an appropriate amount, it may play a role of promoting grain growth during firing or improving crystal structure stability.
  • the a represents the molar ratio of lithium in the lithium nickel-based oxide, and may be 0.8 ⁇ a ⁇ 1.2, 0.85 ⁇ a ⁇ 1.15, or 0.9 ⁇ a ⁇ 1.2.
  • the crystal structure of the lithium nickel-based oxide may be stably formed.
  • b represents the molar ratio of nickel among all metals except lithium in lithium nickel-based oxide, 0.8 ⁇ b ⁇ 1, 0.82 ⁇ b ⁇ 1, 0.83 ⁇ b ⁇ 1, 0.85 ⁇ b ⁇ 1, 0.88 ⁇ b ⁇ 1 or 0.90 ⁇ b ⁇ 1.
  • c represents the cobalt molar ratio of all metals except lithium in lithium nickel-based oxide, 0 ⁇ c ⁇ 0.2, 0 ⁇ c ⁇ 0.18, 0.01 ⁇ c ⁇ 0.17, 0.01 ⁇ c ⁇ 0.15, 0.01 ⁇ c ⁇ 0.12 or It may be 0.01 ⁇ c ⁇ 0.10.
  • the molar ratio of cobalt satisfies the above range, good resistance characteristics and output characteristics may be implemented.
  • d represents the molar ratio of M 1 element in all metals except lithium in lithium nickel-based oxide, 0 ⁇ d ⁇ 0.2, 0 ⁇ d ⁇ 0.18, 0.01 ⁇ d ⁇ 0.17, 0.01 ⁇ d ⁇ 0.15, 0.01 ⁇ d ⁇ 0.12, or 0.01 ⁇ d ⁇ 0.10.
  • the positive electrode active material exhibits excellent structural stability.
  • e represents the molar ratio of M 2 element in all metals except for lithium in the lithium nickel-based oxide, it may be 0 ⁇ e ⁇ 0.1 or 0 ⁇ e ⁇ 0.05.
  • the positive active material according to the present invention if necessary, on the surface of the lithium nickel-based oxide particles, Al, Ti, W, B, F, P, Mg, Ni, Co, Fe, Cr, V, Cu, Ca , Zn, Zr, Nb.
  • a coating layer including at least one coating element selected from the group consisting of Mo, Sr, Sb, Bi, Si and S may be further included.
  • the coating element may be Al, B, Co or a combination thereof.
  • the cathode active material may be included in an amount of 80 wt% to 99 wt%, preferably 85 wt% to 99 wt%, and more preferably 90 wt% to 99 wt%, based on the total weight of the cathode active material layer.
  • the positive electrode current collector various positive electrode current collectors used in the art may be used.
  • the cathode current collector stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, or silver may be used.
  • the cathode current collector may typically have a thickness of 3 ⁇ m to 500 ⁇ m, and fine irregularities may be formed on the surface of the cathode current collector to increase adhesion of the cathode active material.
  • the cathode current collector may be used in various forms such as, for example, a film, sheet, foil, net, porous material, foam, or nonwoven fabric.
  • all or some of the single-particle active material particles may have a core-shell structure in which the particle surface is coated with a conductive coating layer.
  • the conductive coating layer may cover at least some or all of the particles.
  • the conductive coating layer includes a conductive nanomaterial.
  • the present invention coats the surface of single-particle active material particles with a conductive nanomaterial, so that excellent electrical conductivity can be realized without adding a separate conductive material to the positive electrode slurry.
  • the cathode active material layer when a cathode active material coated with a conductive nanomaterial is applied to the surface of the single-particle active material particle, the cathode active material layer may not use a conductive material except for the conductive coating layer.
  • the viscosity of the positive electrode slurry can be reduced and the solid content can be increased, and effects of improving electrode coating processability and electrode adhesion can be obtained.
  • the conductive nanomaterial may be a conductive material having a nano-sized size so as to be smoothly coated on the particles, and the type is not particularly limited.
  • the conductive nanomaterial may be a carbon nanotube or carbon nanoparticle.
  • the conductive nanomaterial may have various shapes, and may be, for example, spherical, scaly, or fibrous.
  • the conductive coating layer may be formed by mixing single-particle active material particles, which are core parts, and conductive nanomaterials, and then heat-treating the conductive nanomaterial.
  • the mixing may be performed by solid-phase mixing or liquid-phase mixing.
  • the positive electrode active material layer includes flaky graphite.
  • the flaky graphite provides a sliding effect to the positive electrode active material, so that the rolling characteristics of the electrode are improved. and can reduce the electrode porosity to a target level. Accordingly, stability, initial resistance characteristics, and charge/discharge efficiency of the battery to which the positive electrode according to the present invention is applied may be improved.
  • the flaky graphite may be included in an amount of 0.1 wt% to 5 wt%, preferably 0.1 wt% to 3 wt%, based on 100 wt% of the positive electrode active material layer.
  • the flaky graphite used in the present invention may have an average particle diameter of 1 ⁇ m to 20 ⁇ m, preferably 2 ⁇ m to 10 ⁇ m, more preferably 3 ⁇ m to 5 ⁇ m. If the size of flaky graphite is too small, it is difficult to realize a desired porosity, and current density may be lowered, resulting in lower capacity. At this time, the average particle diameter of the flaky graphite may be measured by a laser diffraction method (ISO 13320).
  • the flaky graphite may have an aspect ratio of 0.1 to 500, preferably 1 to 100, and more preferably 1 to 30.
  • an effect of reducing electrode resistance by improving conductivity occurs.
  • the flaky graphite has a density of 2.0 g/cm 3 to 2.5 g/cm 3 , preferably 2.1 g/cm 3 to 2.4 g/cm 3 , more preferably 2.2 g/cm 3 to 2.3 g/cm can be 3
  • the porosity of the positive electrode active material layer may be 15% to 23%, preferably 17% to 23%, and more preferably 18% to 23%.
  • the porosity of the positive electrode active material layer satisfies the above range, the electrode density increases to realize excellent capacity and decrease resistance. If the porosity is too low, the impregnability of the electrolyte is poor, and lithium precipitation may occur due to non-impregnation of the electrolyte. If the porosity is too high, the contact between the electrodes is not good, so the resistance increases and the energy density decreases, so the capacity improvement effect is insignificant.
  • the porosity value of the positive electrode active material layer can be achieved by i) the positive electrode active material includes single-particle active material particles and ii) adding flaky graphite to the positive electrode active material.
  • the flaky graphite when included in the cathode active material layer as in the present invention, the flaky graphite provides a sliding effect and fills the gaps of the cathode active material layer during rolling, so that the porosity of the cathode active material layer is the same as above. range can be reduced.
  • the positive electrode may have a loading amount of 570 mg/25 cm 2 or more, preferably 600 mg/25 cm 2 to 800 g/25 cm 2 , and more preferably 600 mg/25 cm 2 to 750 mg/25 cm 2 .
  • a relatively high loading amount of the cathode can be secured. And, through this, it is possible to implement high-capacity characteristics.
  • the positive electrode active material layer may further include a conductive material.
  • the conductive material is used to impart conductivity to the electrode, and any material that does not cause chemical change inside the battery and has electronic conductivity can be used without particular limitation.
  • Specific examples include graphite such as natural graphite or artificial graphite; carbon-based materials such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, summer black, carbon fiber, and carbon nanotube; metal powders or metal fibers such as copper, nickel, aluminum, and silver; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; or conductive polymers such as polyphenylene derivatives, and the like, and one of them alone or a mixture of two or more may be used.
  • the conductive material may be typically included in an amount of 1 wt% to 30 wt%, preferably 1 wt% to 20 wt%, and more preferably 1 wt% to 10 wt%, based on the total weight of the positive electrode active material layer.
  • the conductive material may include carbon nanotubes.
  • the cathode active material may include a multi-walled carbon nanotube having a high specific surface area and a small wall number as a conductive material.
  • the multi-walled carbon nanotubes may be included in 50wt% or more, 70wt% or more, 90wt% or more, or 99wt% or more of 100wt% of the conductive material.
  • the conductive material may be composed of only the multi-walled carbon nanotubes.
  • the multi-walled carbon nanotubes have a BET specific surface area of 300 m 2 /g to 500 m 2 /g. In order to distinguish this from the prior art, it is referred to as 'new CNT'.
  • Carbon nanotubes (existing CNTs) commonly used in the prior art had a BET specific surface area of less than 300 m 2 /g.
  • a comparison of scanning electron microscope images and physical properties (FIG. 23) of the new CNT (FIG. 21) and the conventional CNT (FIG. 22) used in the present invention are as follows.
  • the novel CNTs applied to the present invention are of a bundled type and have a multiwall structure, but have a higher BET and a smaller number of walls and a smaller diameter than conventional CNTs.
  • the secondary particle type positive electrode active material In the case of using the secondary particle type positive electrode active material, sufficient electrical conductivity could be achieved even when the existing CNT was used at a level of 0.4wt% to 0.6wt%.
  • the BET specific surface area is 300 m 2 because the resistance is higher than that of the conventional secondary particle type cathode active material and the electrical conductivity is low due to the small contact area with the conductive material.
  • the content of the conductive material should be 0.9 wt% or more.
  • 24 to 27 are graphs showing sheet resistance and high-temperature lifespan characteristics for each conductive material ratio when single particles or quasi-single particles are applied as the positive electrode active material.
  • the viscosity of the positive electrode slurry must be lowered by reducing the solid content in the positive electrode slurry.
  • the active material content decreases, resulting in poor capacity characteristics.
  • the inventors of the present invention have found that when carbon nanotubes having a BET specific surface area of 300 m 2 /g to 500 m 2 /g are applied as a conductive material together with a cathode active material, which is a single-particle active material particle, , It was confirmed that sufficient electrical conductivity can be secured even with a relatively small amount of carbon nanotubes, and accordingly, the slurry viscosity can be maintained low even when the solid content of the cathode slurry is formed as high as 70 wt% to 80 wt%.
  • the carbon nanotubes used in the present invention may be multi-walled carbon nanotubes having a BET specific surface area of 300 m 2 /g to 500 m 2 /g, preferably 300 m 2 /g to 450 m 2 /g.
  • BET specific surface area satisfies the above range, sufficient electrical conductivity can be secured even with a small amount of carbon nanotubes.
  • the carbon nanotubes may be multi-walled carbon nanotubes having a wall number of 2 to 8, preferably 2 to 6, and more preferably 3 to 6.
  • the carbon nanotubes may have a diameter of 1 nm to 8 nm, preferably 3 nm to 8 nm, and more preferably 3 nm to 6 nm.
  • the carbon nanotubes may be included in an amount of 0.7 wt% or less, preferably 0.3 wt% to 0.7 wt%, and more preferably 0.4 wt% to 0.6 wt%, based on the total weight of the cathode active material layer.
  • the content of the carbon nanotubes satisfies the above range, sufficient electrical conductivity can be achieved, and the solids content in the cathode slurry can be maintained high, thereby forming a high content of the cathode active material in the cathode active material layer. Excellent capacitance characteristics can be realized.
  • the table shown in FIG. 28 shows the case where carbon nanotubes (new CNTs) having a BET specific surface area of 300 m 2 /g to 500 m 2 /g are applied and the carbon nanotubes (existing CNTs) having a BET of 200 m 2 /g or more and less than 300 m 2 /g ) was applied, the solid content and viscosity of the positive electrode slurry and the resistance values of the MP coating layer and the MP interface layer were compared. From the table above, it can be seen that, when the new CNT is applied, the positive electrode slurry has a lower viscosity and excellent electrical conductivity even when the solid content of the positive electrode slurry is higher than that of the conventional CNT.
  • the binder serves to improve the adhesion between the particles of the positive electrode active material and the adhesion between the positive electrode active material and the positive electrode current collector, and specific examples include polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene Polymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene monomer rubber (EPDM rubber), sulfonated-EPDM, styrene butadiene rubber (SBR), fluoro rubber, or various copolymers thereof, and the like, One of these alone or a mixture of two or more may be used.
  • PVDF polyvinylidene fluoride
  • PVDF-co-HFP vinylidene fluoride-hex
  • the binder may be included in an amount of 1 wt% to 30 wt%, preferably 1 wt% to 20 wt%, and more preferably 1 wt% to 10 wt%, based on the total weight of the positive electrode active material layer.
  • Another aspect of the present invention relates to an electrode assembly including the positive electrode and a battery including the same.
  • the electrode assembly includes a negative electrode and a positive electrode, and the positive electrode has the structural characteristics as described above.
  • the electrode assembly may be stacked with a separator interposed between an anode and a cathode to form a stacked or stacked/folded structure, or may be wound to form a jelly roll structure.
  • a separator may be additionally disposed on the outside to prevent contact between the negative electrode and the positive electrode.
  • the negative electrode may include a negative electrode current collector; and an anode active material layer formed on at least one side of the anode current collector.
  • the anode may have a structure in which an anode active material layer is formed on one or both surfaces of a long sheet-shaped anode current collector, and the anode active material layer may include a cathode active material, a conductive material, and a binder.
  • the negative electrode is a negative electrode active material, a conductive material, and a binder on one side or both sides of a long sheet-shaped negative electrode current collector by dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrroly It may be prepared by applying a negative electrode slurry prepared by dispersing in a solvent such as NMP, acetone, or water, removing the solvent of the negative electrode slurry through a drying process, and then rolling. When the negative electrode slurry is applied, a negative electrode including a non-coated portion may be manufactured by not applying the negative electrode slurry to a partial region of the negative electrode current collector, for example, one end of the negative electrode current collector.
  • DMSO dimethyl sulfoxide
  • the anode active material may be a compound capable of reversible intercalation and deintercalation of lithium.
  • the negative electrode active material include carbonaceous materials such as artificial graphite, natural graphite, graphitized carbon fiber, and amorphous carbon; Si, Si-Me alloy (where Me is at least one selected from the group consisting of Al, Sn, Mg, Cu, Fe, Pb, Zn, Mn, Cr, Ti, and Ni), SiO y (where 0 ⁇ y ⁇ 2), silicon-based materials such as Si—C composites; lithium metal thin film; metal materials capable of being alloyed with lithium, such as Sn and Al; and the like, and any one or a mixture of two or more of them may be used.
  • the negative electrode may include a silicon-based negative electrode active material.
  • the silicon-based negative electrode active material is Si, a Si-Me alloy (where Me is at least one selected from the group consisting of Al, Sn, Mg, Cu, Fe, Pb, Zn, Mn, Cr, Ti, and Ni), SiO It may be y (here, 0 ⁇ y ⁇ 2), a Si—C complex, or a combination thereof, preferably SiO y (here, 0 ⁇ y ⁇ 2). Since the silicon-based negative active material has a high theoretical capacity, capacity characteristics may be improved when the silicon-based negative active material is included.
  • the silicon-based negative electrode active material may be doped with Mb metal, and in this case, the Mb metal may be a Group 1 metal element or a Group 2 metal element, and specifically, may be Li, Mg, or the like.
  • the silicon anode active material may be Si, SiO y (here, 0 ⁇ y ⁇ 2), Si—C composite doped with M b metal, or the like.
  • the active material capacity is somewhat lowered due to the doping element, but since it has high efficiency, high energy density can be implemented.
  • FIG 52 is a graph showing a change in energy density according to the content of the silicon-based negative active material and the presence or absence of doping of the silicon-based negative electrode active material in a battery using a mixture of a silicon-based negative active material and a carbon-based negative electrode active material as the negative electrode active material.
  • low efficiency SiO means undoped SiO
  • ultra-high efficiency SiO means Mg/Li doped SiO. 52
  • the energy density is improved as the content of the silicon-based negative active material among the total negative active materials increases.
  • the energy density improvement effect is more excellent as the ratio of the doped silicon-based negative active material among the silicon-based negative active material increases.
  • the silicon-based negative electrode active material may further include a carbon coating layer on the particle surface.
  • the carbon coating amount may be 20 wt% or less, preferably 1 to 20 wt% based on the total weight of the silicon-based negative electrode active material.
  • the carbon coating layer may be formed through a method such as dry coating, wet coating, chemical vapor deposition (CVD), physical vapor deposition (PVD), or atomic layer deposition (ALD).
  • the silicon-based negative active material may have a capacity of 1000 ⁇ 4000mAh / g, and may have an initial efficiency of about 60 ⁇ 95%.
  • D 50 of the silicon-based negative active material may be 3um to 8um, and D min to D max may be included in the range of 0.5um to 30um.
  • the anode may further include a carbon-based anode active material as an anode active material, if necessary.
  • the carbon-based negative electrode active material may be, for example, artificial graphite, natural graphite, graphitized carbon fiber, amorphous carbon, soft carbon, or hard carbon, but is not limited thereto.
  • the mixing ratio of the silicon-based negative electrode active material and the carbon-based negative electrode active material is 1:99 to 20:80, preferably 1:99 to 15:85 by weight. , more preferably from 1:99 to 10:90.
  • the negative active material may be included in an amount of 80 wt % to 99 wt %, preferably 85 wt % to 99 wt %, and more preferably 90 wt % to 99 wt %, based on the total weight of the negative active material layer.
  • the anode active material may further include at least one selected from lithium metal and metal materials capable of alloying with lithium, such as Sn and Al.
  • negative electrode current collectors commonly used in the art may be used, and examples include copper, stainless steel, aluminum, nickel, titanium, fired carbon, carbon on the surface of copper or stainless steel, A surface treated with nickel, titanium, silver, or the like, an aluminum-cadmium alloy, or the like may be used.
  • the negative electrode current collector may have a thickness of typically 3 ⁇ m to 500 ⁇ m, and like the positive electrode current collector, fine irregularities may be formed on the surface of the current collector to enhance bonding strength of the negative electrode active material.
  • the negative electrode current collector may be used in various forms such as a film, sheet, foil, net, porous material, foam, or non-woven fabric.
  • the conductive material is used to impart conductivity to the negative electrode, and any material that does not cause chemical change inside the battery and has electronic conductivity can be used without particular limitation.
  • specific conductive materials include graphite such as natural graphite or artificial graphite; carbon-based materials such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, summer black, carbon fiber, and carbon nanotube; metal powders or metal fibers such as copper, nickel, aluminum, and silver; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; or conductive polymers such as polyphenylene derivatives, and the like, and one of them alone or a mixture of two or more may be used.
  • the conductive material may be typically included in an amount of 1 wt% to 30 wt%, preferably 1 wt% to 20 wt%, and more preferably 1 wt% to 10 wt%, based on the total weight of the negative electrode active material layer.
  • the binder serves to improve adhesion between particles of the anode active material and adhesion between the anode active material and the anode current collector.
  • specific binders include polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile, and carboxymethylcellulose.
  • the binder may be included in an amount of 1 wt% to 30 wt%, preferably 1 wt% to 20 wt%, and more preferably 1 wt% to 10 wt%, based on the total weight of the negative electrode active material layer.
  • the electrode assembly further includes a separator, and the separator is disposed in the electrode assembly in a manner interposed between the negative electrode and the positive electrode.
  • the separator separates the negative electrode and the positive electrode and provides a passage for lithium ions to move, and can be used without particular limitation as long as it is used as a separator in a lithium battery.
  • a porous polymer film for example, a porous polymer film made of polyolefin-based polymers such as ethylene homopolymer, propylene homopolymer, ethylene/butene copolymer, ethylene/hexene copolymer, and ethylene/methacrylate copolymer, or the like
  • a laminated structure of two or more layers of these may be used.
  • conventional porous non-woven fabrics for example, non-woven fabrics made of high-melting glass fibers, polyethylene terephthalate fibers, and the like may be used.
  • a coated separator containing a ceramic component or a polymer material may be used to secure heat resistance or mechanical strength.
  • the battery is a battery case in which an electrode assembly and an electrolyte are housed together, and an appropriate battery case may be selected without particular limitation as long as it is commonly used in the art, such as a pouch type or a metal can type.
  • electrolytes usable in lithium batteries such as organic liquid electrolytes, inorganic liquid electrolytes, solid polymer electrolytes, gel polymer electrolytes, solid inorganic electrolytes, molten inorganic electrolytes, etc. can be used , the type is not particularly limited.
  • the electrolyte may include an organic solvent and a lithium salt.
  • the organic solvent may be used without particular limitation as long as it can serve as a medium through which ions involved in the electrochemical reaction of the battery can move.
  • the organic solvent includes ester-based solvents such as methyl acetate, ethyl acetate, ⁇ -butyrolactone, and ⁇ -caprolactone; ether solvents such as dibutyl ether or tetrahydrofuran; ketone solvents such as cyclohexanone; aromatic hydrocarbon-based solvents such as benzene and fluorobenzene; Dimethylcarbonate (DMC), diethylcarbonate (DEC), methylethylcarbonate (MEC), ethylmethylcarbonate (EMC), ethylene carbonate (EC), propylene carbonate, PC) and other carbonate-based solvents; alcohol solvents such as ethyl alcohol and isopropyl alcohol; nitriles such as R-CN (R is a C2 to C20 straight-chain, branched or
  • carbonate-based solvents are preferred, and cyclic carbonates (eg, ethylene carbonate or propylene carbonate, etc.) having high ion conductivity and high dielectric constant capable of increasing the charge and discharge performance of batteries, and low-viscosity linear carbonate-based compounds ( For example, a mixture of ethyl methyl carbonate, dimethyl carbonate or diethyl carbonate) is more preferable.
  • cyclic carbonates eg, ethylene carbonate or propylene carbonate, etc.
  • low-viscosity linear carbonate-based compounds For example, a mixture of ethyl methyl carbonate, dimethyl carbonate or diethyl carbonate is more preferable.
  • the lithium salt is LiPF 6 , LiClO 4 , LiAsF 6 , LiBF 4 , LiSbF 6 , LiAlO 4 , LiAlCl 4 , LiCF 3 SO 3 , LiC 4 F 9 SO 3 , LiN(C 2 F 5 SO 3 ) 2 , LiN(C 2 F 5 SO 2 ) 2 , LiN(CF 3 SO 2 ) 2 , LiCl, LiI, or LiB(C 2 O 4 ) 2 , and the like may be used.
  • the concentration of the lithium salt is preferably used within the range of 0.1M to 5.0M, preferably 0.1M to 3,0M.
  • concentration of the lithium salt is within the above range, the electrolyte has appropriate conductivity and viscosity, so excellent electrolyte performance can be exhibited, and lithium ions can move effectively.
  • the electrolyte may further include an additive for the purpose of improving lifespan characteristics of a battery, suppressing a decrease in battery capacity, and improving a discharge capacity of a battery.
  • the additives include haloalkylene carbonate-based compounds such as difluoroethylene carbonate, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylene diamine, n-glyme, hexamethyl phosphate tria Mead, nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N,N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrroles, 2-methoxy ethanol or aluminum trichloride alone Alternatively, it may be mixed and used, but is not limited thereto.
  • the additive may be included in an amount of 0.1 wt% to 10
  • the positive electrode may include a loading reducing portion having a smaller loading amount of the positive electrode active material than an adjacent region.
  • the cathode has such a structure, the section of the cathode active material portion may be increased without worrying about precipitation of lithium. Accordingly, the energy density of the electrode assembly may be improved.
  • a method of using a current collector of an electrode as an electrode tab may be used instead of a method of attaching an electrode tab to an electrode.
  • a portion in which the loading amount is reduced occurs at the boundary between the negative electrode active material portion coated with the negative electrode slurry and the negative electrode current collector.
  • metallic lithium may be deposited in the positive electrode active material portion facing the portion where the loading amount is reduced.
  • the N/P ratio is a value obtained by dividing the capacity of the negative electrode calculated considering the area and capacity per mass of the negative electrode by the capacity of the positive electrode obtained considering the area and capacity per mass of the positive electrode, and generally has a value of 1 or more. . That is, the capacity of the negative electrode is increased.
  • the N/P ratio is less than 1, metallic lithium is likely to be precipitated during charging and discharging, which causes rapid deterioration in safety of the battery during high charging and discharging. In other words, the N/P ratio has a significant effect on the safety and capacity of the battery. Due to the risk of precipitation of metallic lithium as described above, the positive electrode active material portion cannot be located in the positive electrode portion facing the portion where the loading amount of the negative electrode is reduced. This causes the energy density of the battery to not increase. Accordingly, the present invention improved the energy density by increasing the section of the positive electrode active material part.
  • FIG. 48 is a view showing an electrode assembly according to an embodiment of the present invention
  • FIG. 49 is a cross-sectional view showing a cross section taken along the line AA′ of FIG. 48 .
  • an electrode assembly 300 includes a cathode 400, an anode 500, and a separator 600.
  • Separator 600 is located between the cathode 400 and the anode 500 .
  • the negative electrode 400, the positive electrode 500, and the separator 600 are wound together to form a jelly roll structure 300S.
  • the jelly roll structure 300S refers to a structure formed by winding the negative electrode 400, the positive electrode 500, and the separator 600.
  • a separator 600 is additionally disposed on the outside to prevent the negative electrode 400 and the positive electrode 500 from contacting each other.
  • the negative electrode 400 includes a negative electrode current collector 410 and a negative electrode active material portion 420 formed by coating a negative electrode active material on the negative electrode current collector 410 .
  • an anode active material portion 420 may be formed by coating both sides of the anode current collector 410 .
  • the negative electrode uncoated portion 430 of the negative electrode current collector 410 to which the negative electrode active material is not coated extends in the first direction d1.
  • the negative electrode uncoated portion 430 extends along one end of the wound negative electrode 400 .
  • the cathode uncoated portion 430 extends beyond the separator 600 in the first direction d1. Accordingly, the cathode uncoated portion 430 may be exposed at one end of the jelly roll structure 300S in the first direction.
  • the positive electrode 500 includes a positive electrode current collector 510 and a positive electrode active material portion 520 formed by coating a positive electrode active material on the positive electrode current collector 510 .
  • the positive electrode active material portion 520 may be formed by coating both surfaces of the positive electrode current collector 510 .
  • the positive electrode uncoated portion 530 to which the positive electrode active material is not applied extends in the second direction d2.
  • the anode uncoated portion 530 extends along one end of the anode 500 to be wound.
  • the anode uncoated portion 530 extends beyond the separator 600 in the second direction d2. Accordingly, the anode uncoated portion 530 may be exposed at one end of the jelly roll structure 300S in the second direction.
  • first direction d1 and the second direction d2 are directions opposite to each other.
  • first direction (d1) and the second direction (d2) may be a direction parallel to the height direction of the jelly roll structure (300S).
  • the electrode assembly 300 is not in the form of attaching a separate electrode tab, but the negative electrode uncoated portion 430 of the anode current collector 410 and the positive electrode uncoated portion 430 of the positive current collector 510 to reduce resistance.
  • This is a form in which the unit 530 itself is used as an electrode tab.
  • the cathode uncoated portion 430 and/or the anode uncoated portion 530 may have substantially the same structure as the electrode uncoated portion described above.
  • the positive electrode active material portion 520 includes a loading reducing portion 500D having a smaller loading amount of the positive electrode active material than an adjacent area, and the loading decreasing portion 500D is in the first direction d1 of the positive electrode 500. ) is located at one end of In addition, more specifically, the loading reducing unit 500D may gradually decrease the loading amount of the cathode active material in the first direction d1.
  • the loading amount means the application amount of the active material per unit area.
  • the portion having a large loading amount may have a relatively thick thickness of the negative active material portion or the positive electrode active material portion because a large amount of negative active material or positive active material is applied to a unit area.
  • a small amount of the negative electrode active material or the positive electrode active material is applied to a unit area, so that the thickness of the negative electrode active material portion or the positive electrode active material portion may be relatively thin.
  • An active material portion may be formed by applying a slurry containing an active material. In this process, a boundary portion in which a loading amount gradually decreases may be formed between the uncoated portion and the active material portion.
  • the negative electrode active material portion 420 may include a negative electrode boundary portion 420B forming a boundary between the negative electrode active material portion 420 and the negative electrode uncoated portion 430 .
  • a loading amount of the negative electrode boundary portion 420B may decrease toward a direction in which the negative electrode uncoated portion 430 is located.
  • the positive electrode active material portion 520 may include a positive electrode boundary portion 520B forming a boundary between the positive electrode active material portion 520 and the positive electrode uncoated portion 530 .
  • a loading amount of the anode boundary portion 520B may decrease toward a direction in which the anode uncoated portion 530 is located.
  • the negative electrode boundary portion 420B or the positive electrode boundary portion 520B in which the loading amount gradually decreases, is naturally generated in the process of applying the slurry containing the active material to the negative current collector 410 or the positive current collector 510.
  • the amount of the positive electrode active material may be smaller than the amount of the negative electrode active material in a region corresponding to the positive boundary portion 520B based on a direction perpendicular to the second direction d2 . Since the N/P ratio has a value greater than 1, the problem of precipitation of metallic lithium does not occur.
  • the problem is the area corresponding to the cathode boundary portion 420B.
  • the amount of the negative electrode active material may be smaller than the amount of the positive electrode active material. This may cause a problem in that metal lithium is precipitated because the N/P ratio has a value smaller than 1.
  • the loading reduction unit 500D is provided on the positive electrode 500, and the negative electrode active material unit 420 is located at a portion corresponding to the loading reduction unit 500D based on a direction perpendicular to the first direction d1. ) may be located. More specifically, the cathode boundary portion 420B may be located at a portion corresponding to the loading reducing portion 500D based on a direction perpendicular to the first direction d1 .
  • the area to which the cathode active material is coated can be increased without fear of lithium precipitation.
  • the loading amount of the positive electrode active material increases as the loading decreasing portion 500D moves in the first direction d1. It may have a gradually decreasing form. Accordingly, it is possible to maintain a high N/P ratio between the negative electrode 400 and the positive electrode 500 in the region where the negative electrode boundary portion 420B is formed, thereby preventing lithium from being deposited.
  • FIG. 42 and 43 are diagrams illustrating a process of manufacturing an anode according to an embodiment of the present invention. Specifically, FIG. 42 is a plan view of the negative electrode sheet viewed from above, and FIG. 43 is a front view of the negative electrode sheet of FIG. 42 viewed from the front.
  • the negative electrode active material portion 420 coated with the negative active material on the negative electrode current collector 410 and the negative electrode active material not coated A step of manufacturing the negative electrode sheet 400S such that the negative electrode uncoated portions 430 are alternately positioned.
  • the negative electrode active material portion 420 may be formed by applying the negative electrode active material along the third direction d3 .
  • the plurality of negative active material portions 420 may be positioned to be spaced apart along the fourth direction d4 by spaced apart application areas along the fourth direction d4 perpendicular to the third direction d3. That is, the coating process may be performed so that the negative electrode uncoated portion 430 is positioned between the plurality of negative electrode active material portions 420 .
  • the third direction d3 and the fourth direction d4 are directions for description based on the negative electrode sheet 400S, and the first direction d1 and the second direction in the jelly roll structure 300S described above ( These are directions unrelated to d2).
  • FIG. 44 is a perspective view showing a negative electrode according to an embodiment of the present invention.
  • FIGS. 42 to 44 as indicated by dotted lines in FIGS. 42 and 43 , slits in the direction parallel to the third direction d3 for the negative electrode uncoated portion 430 and the negative electrode active material portion 420, respectively. ting can be performed. Accordingly, several negative electrodes 400 as shown in FIG. 44 may be manufactured from the negative electrode sheet 400S. That is, the negative electrode 400 of FIG. 44 corresponds to one of several negative electrodes manufactured by slitting the negative electrode sheet 400S of FIGS. 42 and 43 .
  • the negative electrode 400 in which the negative electrode uncoated portion 430 extends to one side may be manufactured by slitting the negative electrode uncoated portion 430 and the negative electrode active material portion 420 of the negative electrode sheet 400S, respectively.
  • a slurry containing the negative electrode active material may be applied on the negative electrode current collector 410.
  • a cathode boundary portion 420B may be formed at the boundary, the loading amount of which decreases toward the direction in which the cathode uncoated portion 430 is located.
  • FIG. 45 and 46 are diagrams illustrating a process of manufacturing an anode according to an embodiment of the present invention. Specifically, FIG. 45 is a plan view of the cathode sheet viewed from above, and FIG. 46 is a front view of the cathode sheet of FIG. 45 viewed from the front.
  • the positive electrode active material portion 520 coated with the positive electrode active material on the positive electrode current collector 510 and the positive electrode active material not coated A step of manufacturing the positive electrode sheet 500S such that the positive electrode uncoated portions 530 are alternately positioned.
  • the cathode active material portion 520 may be formed by applying the cathode active material along the third direction d3.
  • the plurality of positive electrode active material parts 520 may be spaced apart by adjusting the coating interval along the fourth direction d4 perpendicular to the third direction d3. That is, the coating process may be performed so that the positive electrode uncoated portion 530 is positioned between the plurality of positive electrode active material portions 520 .
  • the third direction d3 and the fourth direction d4 are directions for description based on the positive electrode sheet 500S, and the first direction d1 and the second direction in the jelly roll structure 300S described above ( These are directions unrelated to d2).
  • FIG. 47 is a perspective view showing an anode 500 according to an embodiment of the present invention.
  • FIGS. 45 to 47 as indicated by dotted lines in FIGS. 45 and 46 , slits in a direction parallel to the third direction d3 for the positive electrode uncoated portion 530 and the positive electrode active material portion 520, respectively. ting can be performed. Accordingly, several positive electrodes 500 as shown in FIG. 47 may be manufactured from the positive electrode sheet 500S. That is, the positive electrode 500 of FIG. 47 corresponds to one of several positive electrodes manufactured by slitting the positive electrode sheet 500S of FIGS. 45 and 46 .
  • the positive electrode 500 in which the positive electrode uncoated portion 530 extends to one side may be manufactured by slitting the positive electrode uncoated portion 530 and the positive electrode active material portion 520 of the positive electrode sheet 500S, respectively.
  • a slurry containing the positive electrode active material may be applied on the positive electrode current collector 510.
  • An anode boundary portion 520B may be formed at the boundary, the loading amount of which decreases toward the direction where the anode uncoated portion 530 is located.
  • a step of forming a jelly roll structure 300S by winding the prepared negative electrode 400 and the positive electrode 500 together with the separator 600 may be followed.
  • the negative electrode uncoated portion 430 extends beyond the separator 600 in a first direction d1
  • the anode uncoated portion 530 extends in a second direction opposite to the first direction d1. (d2) may extend beyond the separation membrane 600.
  • the positive electrode sheet 500S has a loading reduction region 500DA in which the loading amount of the positive electrode active material is smaller than that of adjacent regions.
  • the loading reduction area 500DA includes there is no particular limitation on the method of forming the loading reduction area 500DA, and for example, it may be formed by adjusting the degree of application of the slurry.
  • the loading reduction region 500DA of the cathode active material portion 520 is slit.
  • the slitted loading reducing area 500DA forms a loading reducing portion 500D in which the loading amount of the positive electrode active material is smaller than that of the adjacent area in the jelly roll structure 300S shown in FIGS. 40 and 41 .
  • a loading reduction area 500DA having a smaller loading amount of the cathode active material than an area adjacent to the cathode active material portion 520 formed on the cathode sheet 500S is formed.
  • the loading reduction area 500DA may be formed in the center of the positive electrode active material portion 520 .
  • the loading reduction area 500DA may be configured such that the loading amount of the positive electrode active material gradually decreases toward the central portion 500C of the loading reduction area 500DA.
  • the loading reduction area By slitting the central portion 500C of the 500DA, the loading reducing portion 500D according to the present embodiment may be provided.
  • the loading reduction area 500DA is formed and the central portion 500C of the loading reduction area 500DA is slit.
  • a loading reducing portion 500D may be provided at one end of the manufactured anode 500, and an anode uncoated portion 530 may be provided at the other end of the anode 500 opposite to the one end. can be provided.
  • the loading reducing portion 500D is at one end of the anode 500 in the first direction d1.
  • the anode uncoated portion 530 may be located at one end of the anode 500 in the second direction d2.
  • the loading amount of the positive electrode active material in the loading reduction area 500D may gradually decrease in the first direction d1.
  • the negative active material portion 420 may be located at a portion corresponding to the loading reducing portion 500D based on a direction perpendicular to the first direction d1. More specifically, in the jelly roll structure 300S, the cathode boundary portion 420B may be located at a portion corresponding to the loading reducing portion 500D based on a direction perpendicular to the first direction d1.
  • the corresponding positional relationship between the loading reducing unit 500D and the cathode boundary unit 420B is omitted because it overlaps with the previously described content.
  • 48 is a view showing an electrode assembly according to a comparative example of the present invention.
  • 49 is a cross-sectional view showing a cross section taken along the cutting line BB′ of FIG. 48;
  • the electrode assembly 600 according to the comparative example of the present invention includes a negative electrode 700, a positive electrode 800, and a separator 900, and includes a negative electrode 700 and a positive electrode 800. And the separator 900 is wound to form a jelly roll structure 600S.
  • the negative electrode 700 may include an anode current collector 710 , an anode active material portion 720 and an anode uncoated portion 730 .
  • the negative electrode uncoated portion 730 may extend in the first direction d1
  • the negative electrode active material portion 720 forms a boundary between the negative electrode active material portion 720 and the negative electrode uncoated portion 730, and the loading amount gradually increases.
  • a decreasing cathode boundary 720B may be included.
  • 50 is a view showing a process of manufacturing an anode 700 according to a comparative example of the present invention.
  • the negative electrode sheet 700S is manufactured so that the negative electrode active material portion 720 and the negative electrode uncoated portion 730 are alternately positioned along the fourth direction d4, the negative electrode uncoated portion 730 and the negative electrode active material
  • a plurality of negative electrodes 700 may be manufactured by slitting the portion 720 .
  • the positive electrode 800 may include a positive electrode current collector 810 , a positive electrode active material portion 820 and a positive electrode uncoated portion 880 .
  • the positive electrode uncoated portion 830 may extend in the second direction d2 opposite to the first direction d1, and the positive active material portion 820 includes the positive electrode active material portion 820 and the positive electrode uncoated portion 830. ) and may include an anode boundary portion 820B in which a loading amount gradually decreases.
  • 51 is a view showing a process of manufacturing an anode 800 according to a comparative example of the present invention.
  • the positive electrode uncoated portion 830 and the positive electrode active material A plurality of anodes 800 may be manufactured by slitting the portion 820 .
  • the electrode assembly 600 according to the comparative example of the present invention may be manufactured by winding the manufactured negative electrode 700 and the positive electrode 800 together with the separator 900 .
  • the electrode assembly 600 according to the comparative example of the present invention may have a structure similar to the electrode assembly 300 according to the present embodiment, except for the loading reducing part 500D (see FIG. 49 ).
  • the positive electrode active material portion ( 820) cannot be located. If the positive electrode active material portion 820 extends to a portion corresponding to the negative electrode boundary portion 720B, the corresponding portion is a portion showing a low N/P ratio value, and metal lithium is highly likely to be deposited. Therefore, in order to prevent lithium precipitation, the length of the positive electrode active material portion 820 has to be limited. That is, the positive electrode active material portion 820 may be formed only in the area B1 as shown, and the positive active material portion 820 may not be formed in the area B2. This results in reducing the length of the positive electrode active material portion 820 due to the negative electrode boundary portion 720B.
  • the positive electrode active material is disposed at a portion corresponding to the negative electrode boundary portion 420B based on a direction perpendicular to the first direction d1.
  • a section 520 in particular a loading reduction section 500D, may be located. Since the loading reducing portion 500D having a smaller loading amount of the positive electrode active material than the adjacent area is provided at a position corresponding to the negative electrode boundary portion 420B, the N/P ratio in the corresponding portion can be maintained high and precipitation of lithium can be prevented. there is.
  • the cathode active material portion 520 may be formed as much as the area A1 and the area A2 in which the cathode active material portion 520 cannot be formed may be reduced.
  • the width of the positive electrode 500 in the height direction compared to the width of the negative electrode 400 in the height direction may be increased to 98% or more.
  • the electrode assembly 300 according to the present embodiment can increase the length of the positive electrode active material part by the amount of the loading reduction part 500D. It may have a higher energy density in a limited space than the electrode assembly 600 according to the comparative example.
  • the present invention is a jelly roll type electrode assembly having a structure in which a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode are wound in one direction, and a cylindrical battery housing in which the electrode assembly is accommodated; and a battery cap disposed above the battery housing to seal the battery housing.
  • the positive electrode according to the present invention includes single-particle active material particles having an average particle diameter D 50 of 5 ⁇ m or less as a positive electrode active material.
  • the cylindrical battery may further include an electrolyte solution, and the above description may be referred to for the electrolyte solution.
  • the electrode assembly may have a structure of a stack type, a stack/folding type, or a jelly roll type as described above.
  • the electrode assembly may have a positive electrode having a loading reducing portion as described above.
  • the amount of heat and gas generated inside the battery also increases. This is because the temperature and pressure inside the battery increase due to such heat and gas, which can cause the battery to ignite or explode. In order to prevent this, heat and gas inside the battery must be properly discharged to the outside, and for this, the cross-sectional area of the battery, which serves as a passage for discharging heat to the outside of the battery, must increase to match the increase in volume.
  • the increase in cross-sectional area does not reach the increase in volume, as the size of the battery increases, the amount of heat generated inside the battery increases, resulting in problems such as increased risk of explosion and reduced output.
  • the present invention proposes a cylindrical battery having a high safety while having a large volume so as to realize a high capacity.
  • the high-loading electrode to which the single-particle or quasi-single-particle type cathode active material is applied may be applied to a cylindrical battery, initial resistance characteristics and charge/discharge efficiency of the cylindrical battery may be improved.
  • the cylindrical battery according to the present invention significantly reduces the amount of gas generated compared to the prior art by applying a single-particle or quasi-single-particle type cathode active material, and thus realizes excellent safety even in a large-sized cylindrical battery having a form factor ratio of 0.4 or more.
  • the cylindrical battery according to the present invention may preferably be a battery having a tab-less structure that does not include an electrode tab, but is not limited thereto.
  • the positive electrode and the negative electrode each include a non-coated portion on which an active material layer is not formed, the positive electrode uncoated portion and the negative electrode uncoated portion are located at the top and bottom of the electrode assembly, respectively, and the positive electrode uncoated portion and a structure in which a current collector plate is coupled to the negative electrode uncoated portion, and the current collector plate is connected to an electrode terminal.
  • a positive electrode slurry was prepared by mixing in N-methylpyrrolidone, and then the positive electrode slurry was coated on one surface of an aluminum current collector sheet, dried at 120° C., and rolled to prepare a positive electrode.
  • conductive material super C
  • SBR styrene-butadiene rubber
  • CMC carboxymethyl cellulose
  • a jelly-roll type electrode assembly was prepared by stacking in the order of separator/anode/separator/cathode with a separator interposed between the positive electrode and the negative electrode prepared as described above, and then winding them.
  • a 4680 cell was manufactured by inserting the electrode assembly prepared as described above into a cylindrical battery housing and then injecting an electrolyte solution.
  • a positive electrode active material As a positive electrode active material, it has a bimodal particle size distribution with a large average particle size D 50 of 9 ⁇ m and a small average particle size D 50 of 4 ⁇ m, and Li[Ni 0.9 Co 0.05 Mn 0.04 Al 0.01 ]O 2 in the form of secondary particles.
  • a 4680 cell was manufactured in the same manner as in Example 1 except for the fact that it was used.
  • each of the 4680 cells manufactured by Example 1 and Comparative Example 1 was placed in a hot box chamber at room temperature, heated up to 130° C. at a heating rate of 5° C./min, and maintained for 30 minutes. Shiki performed a hot box evaluation and measured the temperature change of the battery over time. For accurate evaluation, two hot box evaluations were performed on the cell of Example 1. Measurement results are shown in FIGS. 32 and 33 .
  • FIG. 32 is a graph showing hot box test results of 4680 cells manufactured in Example 1
  • FIG. 33 is a graph showing hot box test results of 4680 cells manufactured in Comparative Example 1.
  • a cathode active material carbon nanotube: PVDF binder was mixed in N-methylpyrrolidone at a weight ratio of 97.8:0.6:1.6 to prepare a cathode slurry.
  • the positive electrode slurry was applied to one surface of an aluminum current collector sheet, dried at 120° C., and then rolled to prepare a positive electrode.
  • conductive material Super C: styrene-butadiene rubber (SBR) : carboxymethyl cellulose (CMC) mixed in water at a weight ratio of 96 : 2 : 1.5 : 0.5
  • SBR styrene-butadiene rubber
  • CMC carboxymethyl cellulose
  • a jelly-roll type electrode assembly was prepared by stacking in the order of separator/anode/separator/cathode with a separator interposed between the positive electrode and the negative electrode prepared as described above, and then winding them.
  • a 4680 cell was manufactured by inserting the electrode assembly prepared as described above into a battery housing and then injecting an electrolyte solution.
  • the positive electrode active material has a bimodal particle size distribution with an average large particle size D 50 of 9 ⁇ m and a small average particle size D 50 of 4 ⁇ m, and a positive electrode active material in the form of secondary particles (composition: Li[Ni 0.9 Co 0.05 Mn 0.04 Al A 4680 cell was manufactured in the same manner as in Example 2-1, except that 0.01 ]O 2 ) was used.
  • each of the 4680 cells manufactured by Example 2-1 and Comparative Example 2-1 was put into a hot box chamber at room temperature, and the temperature was raised to 130 ° C. at a heating rate of 5 ° C./min, After maintaining for 30 minutes, the temperature change of the battery was measured. A case in which thermal runaway and ignition did not occur during the test was marked as Pass, and a case in which thermal runaway and/or ignition occurred was marked as Fail. Also, for the accuracy of the test, the test was performed twice or more for the cells of Examples 2-1 to 2-2.
  • FIGS. 34 and 35 are graph showing hot box test results of 4680 cells manufactured by Sample 1 of Example 2-1 and Comparative Example 2-1
  • FIG. 35 is a graph showing Samples 2 and 3 of Example 2-1 and Example 2 It is a graph showing the hot box test results of 4680 cells manufactured by Samples 1 and 2 of -2 and Comparative Example 2-2.
  • Example 2-1 One 16 139 Pass 2 20.9 141 Pass 3 23.7 137 Pass Example 2-2 One 16.0 148 Pass 2 15.8 147 Pass Comparative Example 2-1 One 17 not measurable Fail Comparative Example 2-2 One 16.2 not measurable Fail
  • the battery is 4680 of Comparative Example 2-1 in which secondary particles were applied as the cathode active material and Comparative Example 2-2 in which the cathode active material in the form of a single particle/similar-single particle having a Dmin of less than 1.0 ⁇ m was applied while the voltage and temperature were maintained stably.
  • the cell can confirm that the battery temperature has risen rapidly.
  • FIG. 36 shows a cross-sectional SEM image of the positive electrode prepared in Example 2-1
  • FIG. 37 shows a cross-sectional SEM image of the positive electrode prepared in Comparative Example 2-1.
  • the positive electrode slurry was applied to one surface of an aluminum current collector sheet, dried, and rolled at a line pressure of 3.0 ton/cm to prepare a positive electrode.
  • the porosity of the cathode active material layer of the cathode prepared as described above was measured, and the porosity was measured to be 17.5%.
  • a positive electrode was prepared in the same manner as in Example 3-1, except that the positive electrode active material, flaky graphite, conductive material, and binder were mixed in a weight ratio of 97.2: 0.6: 0.4: 1.8, and the porosity of the positive electrode active material layer was measured. did The porosity of the positive electrode active material layer was measured to be 19%.
  • a positive electrode was prepared in the same manner as in Example 3-1, except that the positive electrode active material, flaky graphite, conductive material, and binder were mixed in a weight ratio of 97.4: 0.4: 0.4: 1.8, and the porosity of the positive electrode active material layer was measured. did The porosity of the positive electrode active material layer was measured to be 20%.
  • a positive electrode was prepared in the same manner as in Example 3-1, except that the positive electrode active material, flaky graphite, conductive material, and binder were mixed in a weight ratio of 97.6: 0.2: 0.4: 1.8, and the porosity of the positive electrode active material layer was measured. did The porosity of the positive electrode active material layer was measured to be 21%.
  • Example 3-1 Except for the fact that a positive electrode slurry was prepared by mixing the positive electrode active material, the conductive material, and the binder in N-methylpyrrolidone at a weight ratio of 97.8: 0.4: 1.8 without adding flaky graphite, the same as in Example 3-1 A positive electrode was prepared in the same manner, and the porosity of the positive electrode active material layer was measured. The porosity of the positive electrode active material layer was measured to be 24%.
  • a positive electrode slurry was prepared by mixing a positive electrode active material, a conductive material, and a binder in N-methylpyrrolidone at a weight ratio of 97.8: 0.4: 1.8 without adding flaky graphite, and rolling at a linear pressure of 2.0 ton/cm
  • a positive electrode was prepared in the same manner as in Example 3-1 except for, and the porosity of the positive electrode active material layer was measured. The porosity of the positive electrode active material layer was measured to be 30%.
  • Coin half cells including positive electrodes according to Examples 3-1 to 3-4 and Comparative Examples 3-1 and 3-2 were prepared, charged up to 4.25V under a 0.2C current condition, and then 2.5V under a 0.2C current condition. After discharging to V, the charge capacity (mAh/g) and discharge capacity (mAh/g) of each coin half cell were measured. The measurement results are shown in Table 2 below.
  • Example 3-1 1.5 17.5 230.3 209.3 90.9
  • Example 3-2 0.6 19 229.4 206.9 90.2
  • Example 3-3 0.4 20 230.4 207.3 90.0
  • Example 3-4 0.2 21 229.1 205.5 89.7 Comparative Example 3-1 0 24 229.1 204.2 89.1 Comparative Example 3-2 0 30 225.4 199.7 88.6
  • Examples 3-1 to 3-4 using the positive electrode to which flaky graphite was added showed lower porosity and excellent capacity characteristics than Comparative Examples 3-1 to 3-2 can confirm.
  • Example 3-3 in which flaky graphite was added to the positive electrode active material layer, on the basis of SOC10%, was lower than Comparative Example 3-1 and Comparative Example 3-2, which did not contain flaky graphite. You can check. This shows that when flaky graphite is added to the positive electrode active material layer, resistance characteristics at a low SOC are improved.
  • Example 3-1, Example 3-3, and Comparative Example 3-1, with a separator interposed between the positive electrode and the negative electrode, laminated in the order of separator/anode/separator/cathode, and then wound up to form a jelly-roll type electrode assembly was manufactured.
  • a 4680 cell was manufactured by inserting the electrode assembly prepared as described above into a cylindrical battery housing and then injecting an electrolyte solution.
  • conductive material super C
  • SBR styrene-butadiene rubber
  • CMC carboxymethyl cellulose
  • the positive electrode as described above may be the first electrode, and the negative electrode may be the second electrode.
  • the anode may be the second electrode and the cathode may be the first electrode.

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PCT/KR2022/016196 2021-10-22 2022-10-21 원통형 배터리, 그리고 이를 포함하는 배터리 팩 및 자동차 WO2023068886A1 (ko)

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CA3235198A CA3235198A1 (en) 2021-10-22 2022-10-21 Cylindrical battery, and battery pack and vehicle including the same
JP2023544574A JP2024505868A (ja) 2021-10-22 2022-10-21 円筒形バッテリー、それを含むバッテリーパック及び自動車
EP22884107.8A EP4293802A1 (de) 2021-10-22 2022-10-21 Zylindrische sekundärbatterie und batteriepack und fahrzeug damit

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4501361B2 (ja) * 2003-06-05 2010-07-14 パナソニック株式会社 二次電池
JP2016195036A (ja) * 2015-03-31 2016-11-17 株式会社Ｇｓユアサ 蓄電素子及び蓄電素子の製造方法
KR101679413B1 (ko) * 2015-04-03 2016-11-25 (주)오렌지파워 중공형 이차전지
KR101953837B1 (ko) * 2016-12-09 2019-03-05 주식회사 엘 앤 에프 리튬 이차 전지용 양극 활물질, 이의 제조방법 및 이를 포함하는 리튬 이차 전지
CN113346201A (zh) * 2021-05-21 2021-09-03 湖北亿纬动力有限公司 圆柱型电池、电池模组和电池包
KR20210142183A (ko) 2019-03-29 2021-11-24 로빈 펭 모듈식 다용도 공구

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4501361B2 (ja) * 2003-06-05 2010-07-14 パナソニック株式会社 二次電池
JP2016195036A (ja) * 2015-03-31 2016-11-17 株式会社Ｇｓユアサ 蓄電素子及び蓄電素子の製造方法
KR101679413B1 (ko) * 2015-04-03 2016-11-25 (주)오렌지파워 중공형 이차전지
KR101953837B1 (ko) * 2016-12-09 2019-03-05 주식회사 엘 앤 에프 리튬 이차 전지용 양극 활물질, 이의 제조방법 및 이를 포함하는 리튬 이차 전지
KR20210142183A (ko) 2019-03-29 2021-11-24 로빈 펭 모듈식 다용도 공구
CN113346201A (zh) * 2021-05-21 2021-09-03 湖北亿纬动力有限公司 圆柱型电池、电池模组和电池包

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